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Sample records for quantum dot-labeled sushi

  1. Quantum dot labeling of mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Cascio Wayne E

    2007-11-01

    Full Text Available Abstract Background Mesenchymal stem cells (MSCs are multipotent cells with the potential to differentiate into bone, cartilage, fat and muscle cells and are being investigated for their utility in cell-based transplantation therapy. Yet, adequate methods to track transplanted MSCs in vivo are limited, precluding functional studies. Quantum Dots (QDs offer an alternative to organic dyes and fluorescent proteins to label and track cells in vitro and in vivo. These nanoparticles are resistant to chemical and metabolic degradation, demonstrating long term photostability. Here, we investigate the cytotoxic effects of in vitro QD labeling on MSC proliferation and differentiation and use as a cell label in a cardiomyocyte co-culture. Results A dose-response to QDs in rat bone marrow MSCs was assessed in Control (no-QDs, Low concentration (LC, 5 nmol/L and High concentration (HC, 20 nmol/L groups. QD yield and retention, MSC survival, proinflammatory cytokines, proliferation and DNA damage were evaluated in MSCs, 24 -120 hrs post QD labeling. In addition, functional integration of QD labeled MSCs in an in vitro cardiomyocyte co-culture was assessed. A dose-dependent effect was measured with increased yield in HC vs. LC labeled MSCs (93 ± 3% vs. 50% ± 15%, p 90% of QD labeled cells were viable in all groups, however, at 120 hrs increased apoptosis was measured in HC vs. Control MSCs (7.2% ± 2.7% vs. 0.5% ± 0.4%, p Conclusion Fluorescent QDs label MSC effectively in an in vitro co-culture model. QDs are easy to use, show a high yield and survival rate with minimal cytotoxic effects. Dose-dependent effects suggest limiting MSC QD exposure.

  2. Fluorescence Lifetime Imaging of Quantum Dot Labeled DNA Microarrays

    Directory of Open Access Journals (Sweden)

    Jonathan G. Terry

    2009-04-01

    Full Text Available Quantum dot (QD labeling combined with fluorescence lifetime imaging microscopy is proposed as a powerful transduction technique for the detection of DNA hybridization events. Fluorescence lifetime analysis of DNA microarray spots of hybridized QD labeled target indicated a characteristic lifetime value of 18.8 ns, compared to 13.3 ns obtained for spots of free QD solution, revealing that QD labels are sensitive to the spot microenvironment. Additionally, time gated detection was shown to improve the microarray image contrast ratio by 1.8, achieving femtomolar target sensitivity. Finally, lifetime multiplexing based on Qdot525 and Alexa430 was demonstrated using a single excitation-detection readout channel.

  3. Dual-Quantum-Dots-Labeled Lateral Flow Strip Rapidly Quantifies Procalcitonin and C-reactive Protein

    Science.gov (United States)

    Qi, XiaoPing; Huang, YunYe; Lin, ZhongShi; Xu, Liang; Yu, Hao

    2016-03-01

    In the article, a dual-quantum-dots-labeled (dual-QDs-labeled) lateral flow strip (LFS) method was developed for the simultaneous and rapid quantitative detection of procalcitonin (PCT) and C-reactive protein (CRP) in the blood. Two QD-antibody conjugates with different fluorescence emission spectra were produced and sprayed on the LFS to capture PCT and CRP in the blood. Furthermore, a double antibody sandwich method for PCT and, meanwhile, a competitive inhibition method for CRP were employed in the LFS. For PCT and CRP in serum assayed by the dual-QDs-labeled LFS, their detection sensitivities reached 0.1 and 1 ng/mL, respectively, and their linear quantitative detection ranges were from 0.3 to 200 ng/mL and from 50 to 250 μg/mL, respectively. There was little evidence that the PCT and CRP assays would be interfered with each other. The correlations for testing CRP and PCT in clinical samples were 99.75 and 97.02 %, respectively, between the dual-QDs-labeled LFS we developed and commercial methods. The rapid quantification of PCT and CRP on dual-QDs-labeled LFS is of great clinical value to distinguish inflammation, bacterial infection, or viral infection and to provide guidance for the use of antibiotics or other medicines.

  4. CdSe/ZnS Quantum Dots-Labeled Mesenchymal Stem Cells for Targeted Fluorescence Imaging of Pancreas Tissues and Therapy of Type 1 Diabetic Rats

    Science.gov (United States)

    Liu, Haoqi; Tang, Wei; Li, Chao; Lv, Pinlei; Wang, Zheng; Liu, Yanlei; Zhang, Cunlei; Bao, Yi; Chen, Haiyan; Meng, Xiangying; Song, Yan; Xia, Xiaoling; Pan, Fei; Cui, Daxiang; Shi, Yongquan

    2015-06-01

    Mesenchymal stem cells (MSCs) have been used for therapy of type 1 diabetes mellitus. However, the in vivo distribution and therapeutic effects of transplanted MSCs are not clarified well. Herein, we reported that CdSe/ZnS quantum dots-labeled MSCs were prepared for targeted fluorescence imaging and therapy of pancreas tissues in rat models with type 1 diabetes. CdSe/ZnS quantum dots were synthesized, their biocompatibility was evaluated, and then, the appropriate concentration of quantum dots was selected to label MSCs. CdSe/ZnS quantum dots-labeled MSCs were injected into mouse models with type 1 diabetes via tail vessel and then were observed by using the Bruker In-Vivo F PRO system, and the blood glucose levels were monitored for 8 weeks. Results showed that prepared CdSe/ZnS quantum dots owned good biocompatibility. Significant differences existed in distribution of quantum dots-labeled MSCs between normal control rats and diabetic rats ( p therapy of diabetic patients in the near future.

  5. A CCD-based reader combined quantum dots-labeled lateral flow strips for ultrasensitive quantitative detection of anti-HBs antibody.

    Science.gov (United States)

    Zhang, Xueqing; Li, Ding; Wang, Can; Zhi, Xiao; Zhang, Chunlei; Wang, Kan; Cui, Daxiang

    2012-06-01

    Herein we reported a CCD-based reader combined quantum dots-labeled lateral flow strips for ultrasensitive quantitative detection of anti-HBs antibody. The CdTe quantum dots were prepared, then were used to label Hepatitis B Virus surface antigen, and then were fabricated into lateral flow strips. The as-prepared lateral flow strips were used to test different concentration of anti-HBV surface antibodies. The CCD-based reader was designed and fabricated, the quantitative analysis software was compiled, and resultant CCD-based reader system was used for quantitative analysis of examined anti-HBs antibodies on the strips. Results showed that the quantum dots-labeled lateral flow strips could detect the anti-HBs antibody with the limitation concentration of 200 pg/mL, the CCD-based reader system could detect anti-HBs antibody with the sensitivity of 2 pg/mL. In conclusion, the prepared CCD-based reader combined quantum dots-labeled lateral flow strips can be used for quantitative detection of anti-HBs antibody in sera with the sensitivity of 2 pg/mL, and has great potential in applications such as ultrasensitive detection of HBV antigens or antibodies, and other tumor biomarkers in near future.

  6. RGDC Peptide Modified Quantum Dots Labelling and Imaging of Tumor Cells

    Institute of Scientific and Technical Information of China (English)

    GUO Yi; LI Chun-rong; SHEN Huai-bin; ZHANG Xue-zhong; LI Lin-song; YU Qian; XU Li

    2011-01-01

    The labelling and imaging of tumor cells were investigated via arginine-glycine-aspartic acidcysteine(RGDC) peptide-labelled quantum dots(QDs).The results show that RGDC modified QDs can label SMMC-7721 tumor cells and adhere to cellular membrane.In constrast,the unmodified QDs are mainly dispersed around the cell.We also found that the RGDC-QDs can penetrate into the cell at 2 h of incubation.After 6 h of incubation,RGDC-QDs can accumulate in a unique intracellular region.

  7. Identification of quantum dots labeled metallothionein by fast scanning laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Konecna, Marie [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Novotny, Karel [Central European Institute of Technology, Masaryk University, Kamenice 753/5, CZ-625 00 Brno (Czech Republic); Krizkova, Sona [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Blazkova, Iva [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kopel, Pavel [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kaiser, Jozef [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Institute of Physical Engineering, Brno University of Technology, Technicka 2, CZ-616 69 Brno (Czech Republic); Hodek, Petr [Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 00 Prague,Czech Republic (Czech Republic); Kizek, Rene [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); and others

    2014-11-01

    The technique described in this paper allows detection of quantum dots (QDs) specifically deposited on the polystyrene surface by laser-induced breakdown spectroscopy (LIBS). Using LIBS, the distribution of QDs or their conjugates with biomolecules deposited on the surface can be observed, regardless of the fact if they exhibit fluorescence or not. QDs deposited on the specific surface of polystyrene microplate in the form of spots are detected by determination of the metal included in the QDs structure. Cd-containing QDs (CdS, CdTe) stabilized with mercaptopropionic (MPA) or mercaptosuccinic (MSA) acid, respectively, alone or in the form of conjugates with metallothionein (MT) biomolecule are determined by using the 508.58 nm Cd emission line. The observed absolute detection limit for Cd in CdTe QDs conjugates with MT in one spot was 3 ng Cd. Due to the high sensitivity of this technique, the immunoanalysis in combination with LIBS was also investigated. Cd spatial distribution in sandwich immunoassay was detected. - Highlights: • We describe determination of biomolecules labeled with quantum dots by LIBS. • LIBS and immunoassay are applied for the determination of metallothionein. • Metallothionein amount detected by LIBS is 10-times lower compared to ELISA.

  8. Detection of Hepatitis B Virus M204I Mutation by Quantum Dot-Labeled DNA Probe

    Directory of Open Access Journals (Sweden)

    Cheng Zhang

    2017-04-01

    Full Text Available Quantum dots (QDs are semiconductor nanoparticles with a diameter of less than 10 nm, which have been widely used as fluorescent probes in biochemical analysis and vivo imaging because of their excellent optical properties. Sensitive and convenient detection of hepatitis B virus (HBV gene mutations is important in clinical diagnosis. Therefore, we developed a sensitive, low-cost and convenient QDs-mediated fluorescent method for the detection of HBV gene mutations in real serum samples from chronic hepatitis B (CHB patients who had received lamivudine or telbivudine antiviral therapy. We also evaluated the efficiency of this method for the detection of drug-resistant mutations compared with direct sequencing. In CHB, HBV DNA from the serum samples of patients with poor response or virological breakthrough can be hybridized to probes containing the M204I mutation to visualize fluorescence under fluorescence microscopy, where fluorescence intensity is related to the virus load, in our method. At present, the limits of the method used to detect HBV genetic variations by fluorescence quantum dots is 103 IU/mL. These results show that QDs can be used as fluorescent probes to detect viral HBV DNA polymerase gene variation, and is a simple readout system without complex and expensive instruments, which provides an attractive platform for the detection of HBV M204I mutation.

  9. Influence of quantum dot labels on single molecule movement in the plasma membrane

    DEFF Research Database (Denmark)

    Clausen, Mathias P.; Lagerholm, B. Christoffer

    2011-01-01

    Single particle tracking results are very dependent on the probe that is used. In this study we have investigated the influence that functionalized quantum dots (QDs) have on the recorded movement in single molecule tracking experiments of plasma membrane species in live cells. Potential issues...... in labeling single molecules with QDs (and other particles e.g. gold particles) are induction of cross-linking of the target molecules, which can cause activation of signaling pathways or reduced mobility, and steric hindrance as a result of the probe size. Cross-linking can be a result of the multivalent...... for simultaneous investigations of different plasma membrane species in order to discriminate the effect of the label from differences in movement of the target molecules....

  10. Influence of quantum dot labels on single molecule movement in the plasma membrane

    DEFF Research Database (Denmark)

    Clausen, Mathias P.; Lagerholm, B. Christoffer

    2011-01-01

    Single particle tracking results are very dependent on the probe that is used. In this study we have investigated the influence that functionalized quantum dots (QDs) have on the recorded movement in single molecule tracking experiments of plasma membrane species in live cells. Potential issues...... in labeling single molecules with QDs (and other particles e.g. gold particles) are induction of cross-linking of the target molecules, which can cause activation of signaling pathways or reduced mobility, and steric hindrance as a result of the probe size. Cross-linking can be a result of the multivalent...... functionalization tag (e.g. streptavidin (sAv)) or the presence of multiple mono- or multivalent functionalization tags per QD. In this work, we have compared commercially available sAv-QDs of different sizes with custom prepared Co enzyme A (CoA)-QDs both targeting a GPI-anchored protein modified with either...

  11. Development of a quantum-dot-labelled magnetic immunoassay method for circulating colorectal cancer cell detection

    Institute of Scientific and Technical Information of China (English)

    Maria Gazouli; Anna Lyberopoulou; Pericles Pericleous; Spyros Rizos; Gerassimos Aravantinos; Nikolaos Nikiteas; Nicholas P Anagnou

    2012-01-01

    AIM:To detect of colorectal cancer (CRC) circulating tumour cells (CTCs) surface antigens,we present an assay incorporating cadmium selenide quantum dots (QDs) in these paper.METHODS:The principle of the assay is the immunomagnetic separation of CTCs from body fluids in conjunction with QDs,using specific antibody biomarkers:epithelial cell adhesion molecule antibody,and monoclonal cytokeratin 19 antibody.The detection signal was acquired from the fluorescence signal of QDs.For the evaluation of the performance,the method under study was used to isolate the human colon adenocarcinoma cell line (DLD-1) and CTCs from CRC patients' peripheral blood.RESULTS:The minimum detection limit of the assay was defined to 10 DLD-1 CRC cells/mL as fluorescence was measured with a spectrofluorometer.Fluorescenceactivated cell sorting analysis and Real Time RT-PCR,they both have also been used to evaluate the performance of the described method.In conclusion,we developed a simple,sensitive,efficient and of lower cost (than the existing ones) method for the detection of CRC CTCs in human samples.We have accomplished these results by using magnetic bead isolation and subsequent QD fluorescence detection.CONCLUSION:The method described here can be easily adjusted for any other protein target of either the CTC or the host.

  12. A molecular beacon microarray based on a quantum dot label for detecting single nucleotide polymorphisms.

    Science.gov (United States)

    Guo, Qingsheng; Bai, Zhixiong; Liu, Yuqian; Sun, Qingjiang

    2016-03-15

    In this work, we report the application of streptavidin-coated quantum dot (strAV-QD) in molecular beacon (MB) microarray assays by using the strAV-QD to label the immobilized MB, avoiding target labeling and meanwhile obviating the use of amplification. The MBs are stem-loop structured oligodeoxynucleotides, modified with a thiol and a biotin at two terminals of the stem. With the strAV-QD labeling an "opened" MB rather than a "closed" MB via streptavidin-biotin reaction, a sensitive and specific detection of label-free target DNA sequence is demonstrated by the MB microarray, with a signal-to-background ratio of 8. The immobilized MBs can be perfectly regenerated, allowing the reuse of the microarray. The MB microarray also is able to detect single nucleotide polymorphisms, exhibiting genotype-dependent fluorescence signals. It is demonstrated that the MB microarray can perform as a 4-to-2 encoder, compressing the genotype information into two outputs.

  13. Trace of antibody to myeloperoxidase with nanocrystal quantum dot labeled antibody recognizing activating neutrophils

    Science.gov (United States)

    Hoshino, Akiyoshi; Nagao, Tomokazu; Yamamoto, Kenji; Suzuki, Kazuo

    2006-02-01

    It is assumed that activated neutrophils contribute to the development of anti-neutrophil cytoplasmic auto-antibody (ANCA)-associated vasculitis due to the association of myelopeoxidase(MPO)-ANCA with MPO expressed on the surface of activated neutrophils. FITC-labeled antibody (Ab) used widely are not suitable for neutrophil examination because of the labile fluorescence emission of FITC. Therefore, it is necessary to develop specific fluorescent probes for MPO detection in neutrophils in vivo. Recently, fluorescent nanocrystal quantum dots (QDs) have been used for biotechnological and medical applications because of their greater and far longer fluorescence in. QDs have several advantages over organic fluorophores: high luminescence, far longer stability against photobleaching, and a range of fluorescence wavelengths from blue to infrared, depending on particle size. Thus, we examined the role of MPO and the Ab to MPO in the pathogenesis of glomerulonephritis associated with MPO-ANCA in experimental glomerulonephritis mice using QDs. We demonstrated the QD-conjugated anti-MPO Ab visualized the expression of MPO on the neutrophil surface after stimulation with proinflammatory cytokines. In addition, QD immuno-conjugates with anti-recombinant murine MPO (rmMPO) Ab revealed the trafficking of MPO-ANCA in vivo. Deceleration of blood flow in kidney vessels occurred in model mice, in which serum proteins including anti-rmMPO Ab were leaked out from collapsed glomeruli into the proximal tubule. Thus, sustained MPO expression on the neutrophil surface was significantly related to glomerulonephritis. These results indicate that the expressed MPO on the activated neutrophils with anti-MPO Ab may coordinately play essential roles in the initial steps for the development of glomerulonephritis.

  14. Magnetic Electrochemical Immunoassays with Quantum Dot Labels for Detection of Phosphorylated Acetylcholinesterase in Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hua; Wang, Jun; Timchalk, Charles; Lin, Yuehe

    2008-11-01

    A new magnetic electrochemical immunoassay has been developed as a tool for biomonitoring exposures to organophosphate (OP) compounds, e.g., insecticides and chemical nerve agents, by directly detecting organophosphorylated acetylcholinesterase (OP-AChE). This immunoassay uniquely incorporates highly efficient magnetic separation with ultrasensitive square wave voltammetry (SWV) analysis with quantum dots (QDs) as labels. A pair of antibodies was used to achieve the specific recognition of OP-AChE that was prepared with paraoxon as an OP model agent. Antiphosphoserine polyclonal antibodies were anchored on amorphous magnetic particles preferably chosen to capture OP-AChE from the sample matrixes by binding their phosphoserine moieties that were exposed through unfolding the protein adducts. This was validated by electrochemical examinations and enzyme-linked immunosorbent assays. Furthermore, antihuman AChE monoclonal antibodies were labeled with cadmium-source QDs to selectively recognize the captured OP-AChE, as characterized by transmission electron microscopy. The subsequent electrochemical SWV analysis of the cadmium component released by acid from the coupled QDs was conducted on disposable screen-printed electrodes. Experimental results indicated that the SWV-based immunoassays could yield a linear response over a broad concentration range of 0.3-300 ng/mL OP-AChE in human plasma with a detection limit of 0.15 ng/mL. Such a novel electrochemical immunoassay holds great promise as a simple, selective, sensitive, and field-deployable tool for the effective biomonitoring and diagnosis of potential exposures to nerve agents and pesticides.

  15. Simultaneous Quantitative Detection of Helicobacter Pylori Based on a Rapid and Sensitive Testing Platform using Quantum Dots-Labeled Immunochromatiographic Test Strips.

    Science.gov (United States)

    Zheng, Yu; Wang, Kan; Zhang, Jingjing; Qin, Weijian; Yan, Xinyu; Shen, Guangxia; Gao, Guo; Pan, Fei; Cui, Daxiang

    2016-12-01

    Quantum dots-labeled urea-enzyme antibody-based rapid immunochromatographic test strips have been developed as quantitative fluorescence point-of-care tests (POCTs) to detect helicobacter pylori. Presented in this study is a new test strip reader designed to run on tablet personal computers (PCs), which is portable for outdoor detection even without an alternating current (AC) power supply. A Wi-Fi module was integrated into the reader to improve its portability. Patient information was loaded by a barcode scanner, and an application designed to run on tablet PCs was developed to handle the acquired images. A vision algorithm called Kmeans was used for picture processing. Different concentrations of various human blood samples were tested to evaluate the stability and accuracy of the fabricated device. Results demonstrate that the reader can provide an easy, rapid, simultaneous, quantitative detection for helicobacter pylori. The proposed test strip reader has a lighter weight than existing detection readers, and it can run for long durations without an AC power supply, thus verifying that it possesses advantages for outdoor detection. Given its fast detection speed and high accuracy, the proposed reader combined with quantum dots-labeled test strips is suitable for POCTs and owns great potential in applications such as screening patients with infection of helicobacter pylori, etc. in near future.

  16. A CCD-based reader combined with CdS quantum dot-labeled lateral flow strips for ultrasensitive quantitative detection of CagA

    Science.gov (United States)

    Gui, Chen; Wang, Kan; Li, Chao; Dai, Xuan; Cui, Daxiang

    2014-02-01

    Immunochromatographic assays are widely used to detect many analytes. CagA is proved to be associated closely with initiation of gastric carcinoma. Here, we reported that a charge-coupled device (CCD)-based test strip reader combined with CdS quantum dot-labeled lateral flow strips for quantitative detection of CagA was developed, which used 365-nm ultraviolet LED as the excitation light source, and captured the test strip images through an acquisition module. Then, the captured image was transferred to the computer and was processed by a software system. A revised weighted threshold histogram equalization (WTHE) image processing algorithm was applied to analyze the result. CdS quantum dot-labeled lateral flow strips for detection of CagA were prepared. One hundred sera samples from clinical patients with gastric cancer and healthy people were prepared for detection, which demonstrated that the device could realize rapid, stable, and point-of-care detection, with a sensitivity of 20 pg/mL.

  17. Simultaneous Quantitative Detection of Helicobacter Pylori Based on a Rapid and Sensitive Testing Platform using Quantum Dots-Labeled Immunochromatiographic Test Strips

    Science.gov (United States)

    Zheng, Yu; Wang, Kan; Zhang, Jingjing; Qin, Weijian; Yan, Xinyu; Shen, Guangxia; Gao, Guo; Pan, Fei; Cui, Daxiang

    2016-02-01

    Quantum dots-labeled urea-enzyme antibody-based rapid immunochromatographic test strips have been developed as quantitative fluorescence point-of-care tests (POCTs) to detect helicobacter pylori. Presented in this study is a new test strip reader designed to run on tablet personal computers (PCs), which is portable for outdoor detection even without an alternating current (AC) power supply. A Wi-Fi module was integrated into the reader to improve its portability. Patient information was loaded by a barcode scanner, and an application designed to run on tablet PCs was developed to handle the acquired images. A vision algorithm called Kmeans was used for picture processing. Different concentrations of various human blood samples were tested to evaluate the stability and accuracy of the fabricated device. Results demonstrate that the reader can provide an easy, rapid, simultaneous, quantitative detection for helicobacter pylori. The proposed test strip reader has a lighter weight than existing detection readers, and it can run for long durations without an AC power supply, thus verifying that it possesses advantages for outdoor detection. Given its fast detection speed and high accuracy, the proposed reader combined with quantum dots-labeled test strips is suitable for POCTs and owns great potential in applications such as screening patients with infection of helicobacter pylori, etc. in near future.

  18. Tracking of Single Quantum Dot Labeled EcoRV Sliding along DNA Manipulated by Double Optical Tweezers

    OpenAIRE

    Biebricher, Andreas; Wende, Wolfgang; Escudé, Christophe; Pingoud, Alfred; Desbiolles, Pierre

    2009-01-01

    Fluorescence microscopy provides a powerful method to directly observe single enzymes moving along a DNA held in an extended conformation. In this work, we present results from single EcoRV enzymes labeled with quantum dots which interact with DNA manipulated by double optical tweezers. The application of quantum dots facilitated accurate enzyme tracking without photobleaching whereas the tweezers allowed us to precisely control the DNA extension. The labeling did not affect the biochemical a...

  19. Microfluidic bead-based multienzyme-nanoparticle amplification for detection of circulating tumor cells in the blood using quantum dots labels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, He, E-mail: mzhang_he@126.com; Fu, Xin; Hu, Jiayi; Zhu, Zhenjun

    2013-05-24

    Graphical abstract: A microfluidic beads-based nucleic acid sensor for sensitive detection of circulating tumor cells (CTCs) in the blood using multienzyme-nanoparticle amplification and quantum dots labels was developed. The chip-based CTCs analysis could detect reverse transcription-polymerase chain reaction (RT-PCR) products of tumor cell as low as 1 tumor cell (e.g. CEA expressing cell) in 1 mL blood sample. This microfluidic beads-based nucleic acid sensor is a promising platform for disease-related nucleic acid molecules at the lowest level at their earliest incidence. -- Highlights: •Combination of microfluidic bead-based platform and enzyme–probe–AuNPs is proposed. •The developed nucleic acid sensor could respond to 5 fM of tumor associated DNA. •Microfluidic platform and multienzyme-labeled AuNPs greatly enhanced sensitivity. •The developed nucleic acid sensor could respond to RT-PCR products of tumor cell as low as 1 tumor cell in 1 mL blood sample. •We report a sensitive nucleic acid sensor for detection of circulating tumor cells. -- Abstract: This study reports the development of a microfluidic bead-based nucleic acid sensor for sensitive detection of circulating tumor cells in blood samples using multienzyme-nanoparticle amplification and quantum dot labels. In this method, the microbeads functionalized with the capture probes and modified electron rich proteins were arrayed within a microfluidic channel as sensing elements, and the gold nanoparticles (AuNPs) functionalized with the horseradish peroxidases (HRP) and DNA probes were used as labels. Hence, two signal amplification approaches are integrated for enhancing the detection sensitivity of circulating tumor cells. First, the large surface area of Au nanoparticle carrier allows several binding events of HRP on each nanosphere. Second, enhanced mass transport capability inherent from microfluidics leads to higher capture efficiency of targets because continuous flow within micro

  20. Analysis of the fluctuations of a single-tethered, quantum-dot labeled DNA molecule in shear flow

    Energy Technology Data Exchange (ETDEWEB)

    Laube, K; Guenther, K; Mertig, M, E-mail: michael.mertig@tu-dresden.de [Professur fuer Physikalische Chemie, Mess- und Sensortechnik, Technische Universitaet Dresden, 01062 Dresden (Germany)

    2011-05-11

    A novel technique for analyzing the conformational fluctuations of a single, surface-tethered DNA molecule by fluorescence microscopy is reported. Attaching a nanometer-sized fluorescent quantum dot to the free end of a {lambda}-phage DNA molecule allows us to study the fluctuations of a native DNA molecule without the mechanical properties being altered by fluorescent dye staining. We report on the investigation of single-tethered DNA in both the unperturbed and the shear flow induced stretched state. The dependence of the observed fractional extension and the magnitude of fluctuations on the shear rate can be qualitatively interpreted by Brochard's stem-and-flower model. The cyclic dynamics of a DNA molecule is directly observed in the shear flow experiment.

  1. Transformation of cell-derived microparticles into quantum-dot-labeled nanovectors for antitumor siRNA delivery.

    Science.gov (United States)

    Chen, Gang; Zhu, Jun-Yi; Zhang, Zhi-Ling; Zhang, Wei; Ren, Jian-Gang; Wu, Min; Hong, Zheng-Yuan; Lv, Cheng; Pang, Dai-Wen; Zhao, Yi-Fang

    2015-01-12

    Cell-derived microparticles (MPs) have been recently recognized as critical intercellular information conveyors. However, further understanding of their biological behavior and potential application has been hampered by the limitations of current labeling techniques. Herein, a universal donor-cell-assisted membrane biotinylation strategy was proposed for labeling MPs by skillfully utilizing the natural membrane phospholipid exchange of their donor cells. This innovative strategy conveniently led to specific, efficient, reproducible, and biocompatible quantum dot (QD) labeling of MPs, thereby reliably conferring valuable traceability on MPs. By further loading with small interference RNA, QD-labeled MPs that had inherent cell-targeting and biomolecule-conveying ability were successfully employed for combined bioimaging and tumor-targeted therapy. This study provides the first reliable and biofriendly strategy for transforming biogenic MPs into functionalized nanovectors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Microbial detection in microfluidic devices through dual staining of quantum dots-labeled immunoassay and RNA hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qing [Division of Environmental Science and Engineering, National University of Singapore, Blk E1A, 07-03, Engineering Drive 2, Singapore 117576 (Singapore); Zhu Liang [Division of Environmental Science and Engineering, National University of Singapore, Blk E1A, 07-03, Engineering Drive 2, Singapore 117576 (Singapore); Feng Hanhua [Institute of Microelectronics (Singapore); Ang, Simon [Department of Electrical Engineering, University of Arkansas, Fayetteville (United States); Chau, F.S. [Department of Mechanical Engineering, National University of Singapore (Singapore); Liu, W.-T. [Division of Environmental Science and Engineering, National University of Singapore, Blk E1A, 07-03, Engineering Drive 2, Singapore 117576 (Singapore)]. E-mail: cveliuwt@nus.edu.sg

    2006-01-18

    This paper reported the development of a microfludic device for the rapid detection of viable and nonviable microbial cells through dual labeling by fluorescent in situ hybridization (FISH) and quantum dots (QDs)-labeled immunofluorescent assay (IFA). The coin sized device consists of a microchannel and filtering pillars (gap = 1-2 {mu}m) and was demonstrated to effectively trap and concentrate microbial cells (i.e. Giardia lamblia). After sample injection, FISH probe solution and QDs-labeled antibody solution were sequentially pumped into the device to accelerate the fluorescent labeling reactions at optimized flow rates (i.e. 1 and 20 {mu}L/min, respectively). After 2 min washing for each assay, the whole process could be finished within 30 min, with minimum consumption of labeling reagents and superior fluorescent signal intensity. The choice of QDs 525 for IFA resulted in bright and stable fluorescent signal, with minimum interference with the Cy3 signal from FISH detection.

  3. Correlative fluorescence and scanning transmission electron microscopy of quantum dot-labeled proteins on whole cells in liquid.

    Science.gov (United States)

    Peckys, Diana B; Bandmann, Vera; de Jonge, Niels

    2014-01-01

    Correlative fluorescence microscopy combined with scanning transmission electron microscopy (STEM) of cells fully immersed in liquid is a new methodology with many application areas. Proteins, in live cells immobilized on microchips, are labeled with fluorescent quantum dot nanoparticles. In this protocol, the epidermal growth factor receptor (EGFR) is labeled. The cells are fixed after a selected labeling time, for example, 5 min as needed to form EGFR dimers. The microchip with cells is then imaged with fluorescence microscopy. Thereafter, STEM can be accomplished in two ways. The microchip with the labeled cells and one microchip with a spacer are assembled into a special microfluidic device and imaged with dedicated high-voltage STEM. Alternatively, thin edges of cells can be studied with environmental scanning electron microscopy with a STEM detector, by placing a microchip with cells in a cooled wet environment.

  4. Clathrin-mediated endocytosis in living host cells visualized through quantum dot labeling of infectious hematopoietic necrosis virus.

    Science.gov (United States)

    Liu, Haibin; Liu, Yi; Liu, Shulin; Pang, Dai-Wen; Xiao, Gengfu

    2011-07-01

    Infectious hematopoietic necrosis virus (IHNV) is an important fish pathogen that infects both wild and cultured salmonids. As a species of the genus Novirhabdovirus, IHNV is a valuable model system for exploring the host entry mechanisms of rhabdoviruses. In this study, quantum dots (QDs) were used as fluorescent labels for sensitive, long-term tracking of IHNV entry. Using live-cell fluorescence microscopy, we found that IHNV is internalized through clathrin-coated pits after the virus binds to host cell membranes. Pretreatment of host cells with chlorpromazine, a drug that blocks clathrin-mediated endocytosis, and clathrin light chain (LCa) depletion using RNA interference both resulted in a marked reduction in viral entry. We also visualized transport of the virus via the cytoskeleton (i.e., actin filaments and microtubules) in real time. Actin polymerization is involved in the transport of endocytic vesicles into the cytosol, whereas microtubules are required for the trafficking of clathrin-coated vesicles to early endosomes, late endosomes, and lysosomes. Disrupting the host cell cytoskeleton with cytochalasin D or nocodazole significantly impaired IHNV infectivity. Furthermore, infection was significantly affected by pretreating the host cells with bafilomycin A1, a compound that inhibits the acidification of endosomes and lysosomes. Strong colocalizations of IHNV with endosomes indicated that the virus is internalized into these membrane-bound compartments. This is the first report in which QD labeling is used to visualize the dynamic interactions between viruses and endocytic structures; the results presented demonstrate that IHNV enters host cells via clathrin-mediated endocytic, cytoskeleton-dependent, and low-pH-dependent pathways.

  5. One-pot synthesis of quantum dot-labeled hydrophilic molecularly imprinted polymer nanoparticles for direct optosensing of folic acid in real, undiluted biological samples.

    Science.gov (United States)

    Yang, Yaqiong; Wang, Zhengzheng; Niu, Hui; Zhang, Huiqi

    2016-12-15

    A facile and efficient one-pot approach for the synthesis of quantum dot (QD)-labeled hydrophilic molecularly imprinted polymer (MIP) nanoparticles for direct optosensing of folic acid (FA) in the undiluted bovine and porcine serums is described. Hydrophilic macromolecular chain transfer agent-mediated reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization was used to implement the molecular imprinting of FA in the presence of CdTe quantum dots (QDs). The resulting FA-imprinted polymer nanoparticles with surface-grafted hydrophilic poly(glyceryl monomethacrylate) brushes and QDs labeling not only showed outstanding specific molecular recognition toward FA in biological samples, but also exhibited good photostability, rapid binding kinetics, and obvious template binding-induced fluorescence quenching. These characteristics make them a useful fluorescent chemosensor for directly and selectively optosensing FA in the undiluted bovine and porcine serums, with its limit of detection being 0.025μM and average recoveries ranging from 98% to 102%, even in the presence of several interfering compounds. This advanced fluorescent MIP chemosensor is highly promising for rapid quantification of FA in such applications as clinical diagnostics and food analysis.

  6. Sensitive Bioanalysis Based on in-Situ Droplet Anodic Stripping Voltammetric Detection of CdS Quantum Dots Label after Enhanced Cathodic Preconcentration.

    Science.gov (United States)

    Qin, Xiaoli; Wang, Linchun; Xie, Qingji

    2016-08-23

    We report a protocol of CdS-labeled sandwich-type amperometric bioanalysis with high sensitivity, on the basis of simultaneous chemical-dissolution/cathodic-enrichment of the CdS quantum dot biolabel and anodic stripping voltammetry (ASV) detection of Cd directly on the bioelectrode. We added a microliter droplet of 0.1 M aqueous HNO₃ to dissolve CdS on the bioelectrode and simultaneously achieved the potentiostatic cathodic preconcentration of Cd by starting the potentiostatic operation before HNO₃ addition, which can largely increase the ASV signal. Our protocol was used for immunoanalysis and aptamer-based bioanalysis of several proteins, giving limits of detection of 4.5 fg·mL(-1) for human immunoglobulin G, 3.0 fg·mL(-1) for human carcinoembryonic antigen (CEA), 4.9 fg·mL(-1) for human α-fetoprotein (AFP), and 0.9 fM for thrombin, which are better than many reported results. The simultaneous and sensitive analysis of CEA and AFP at two screen-printed carbon electrodes was also conducted by our protocol.

  7. Sensitive Bioanalysis Based on in-Situ Droplet Anodic Stripping Voltammetric Detection of CdS Quantum Dots Label after Enhanced Cathodic Preconcentration

    Directory of Open Access Journals (Sweden)

    Xiaoli Qin

    2016-08-01

    Full Text Available We report a protocol of CdS-labeled sandwich-type amperometric bioanalysis with high sensitivity, on the basis of simultaneous chemical-dissolution/cathodic-enrichment of the CdS quantum dot biolabel and anodic stripping voltammetry (ASV detection of Cd directly on the bioelectrode. We added a microliter droplet of 0.1 M aqueous HNO3 to dissolve CdS on the bioelectrode and simultaneously achieved the potentiostatic cathodic preconcentration of Cd by starting the potentiostatic operation before HNO3 addition, which can largely increase the ASV signal. Our protocol was used for immunoanalysis and aptamer-based bioanalysis of several proteins, giving limits of detection of 4.5 fg·mL−1 for human immunoglobulin G, 3.0 fg·mL−1 for human carcinoembryonic antigen (CEA, 4.9 fg·mL−1 for human α-fetoprotein (AFP, and 0.9 fM for thrombin, which are better than many reported results. The simultaneous and sensitive analysis of CEA and AFP at two screen-printed carbon electrodes was also conducted by our protocol.

  8. Nitrogen-doped graphene quantum dots-labeled epitope imprinted polymer with double templates via the metal chelation for specific recognition of cytochrome c.

    Science.gov (United States)

    Yan, Yun-Jing; He, Xi-Wen; Li, Wen-You; Zhang, Yu-Kui

    2017-05-15

    A novel fluorescent sensor nitrogen-doped graphene quantum dots (N-GQDs)/SiO2/molecular imprinting polymer(N-GQDs/SiO2/MIP)was fabricated by surface imprinting and epitope imprinting to recognize and detect the target protein cytochrome c (Cyt C) with fluorescence quenching. In the polymerization process, the C- and N-terminal nonapeptides of Cyt C were selected as the double templates which were fixed by functional monomer (zinc acrylate) through metal chelation and steady six-membered ring. The linear range of fluorescence quenching for this receptor towards Cyt C was 0.20-60μM, and the detection limit was 0.11μM. The precision for six times replicate determination of Cyt C at 30μM was 1.20%, and the imprinting factor (IF) was 3.06. The recoveries of the material to Cyt C in urine were 99.3-114.0%. In brief, this work proposed a strategy to prepare a new type fluorescent imprinting polymer based on N-GQDs and provided an attractive perspective for the detection of protein by using the combination of N-GQDs and molecular imprinting technique.

  9. Quantum dots-labeled strip biosensor for rapid and sensitive detection of microRNA based on target-recycled nonenzymatic amplification strategy.

    Science.gov (United States)

    Deng, Huaping; Liu, Qianwen; Wang, Xin; Huang, Ru; Liu, Hongxing; Lin, Qiumei; Zhou, Xiaoming; Xing, Da

    2017-01-15

    MicroRNAs (miRNAs) have been proved to be potential biomarkers in early cancer diagnosis. It is of great significance for rapid and sensitive detection of miRNAs, particularly with point-of-care (POC) diagnosis. Herein, it is the first time to construct quantum dots (QDs)-labeled strip biosensor based on target-recycled nonenzymatic amplification strategy for miRNA detection. In the system, QDs were served as bright, photostable signal labels, which endow this biosensor with good detection efficiency. Moreover, a target-recycled amplification strategy relies on sequence-specific hairpins strand displacement process without the assistance of enzymes, was introduced to further improve the sensitivity. Meanwhile eliminating the requirement of environment-susceptible enzyme protein makes it easy to preserve and enhances the stability and reproducibility of this sensor. Benefiting from these outstanding characteristics, this platform exhibited a good detection sensitivity range from 2fmol to 200fmol with a limit of 200amol, using only 20μL of sample within 80min. The assay was also 10-fold more sensitive than that with a conventional colloidal gold-based test strip for miRNA detection. Additionally, the analysis of miRNA in various tumor cell extracts was in accordance with the performance of quantitative realtime polymerase chain reaction (qRT-PCR). Clinical tumor samples were also tested, and 16 of 20 samples gave out positive signals, which demonstrated the practical application capacity of the biosensor. Therefore, the proposed biosensor holds great promise for potential POC applications and early cancer diagnosis.

  10. Application of quantum dots labeling technique in induced pluripotent stem cells%CdSe/ZnS核壳结构量子点用于人诱导多能干细胞标记的研究

    Institute of Scientific and Technical Information of China (English)

    谭美华; 陈建苏; 陈剑; 吴静; 招志毅; 戴应; 李善义

    2013-01-01

    characteristics of iPSCs.Objective This study was to investigate the feasibility and stability of labeling iPSCs with quantum dots.Methods Human umbilical mesenchymal stromal cells-iPSC lines were cultured and amplified on matrigel,and the characteristics of iPSCs were evaluated by immunofluorescence.Different concentrations (5.0,7.5 and 10.0 nmol/L) of quantum dots with a CdSe/ZnS nuclear shell structure were used to label iPSCs after passaging and proliferation.The labeling outcome was observed with a three-dimensional deconvolution real-time live cells imaging system.The labeled iPSCs were subsequently cultivated,and then changes in fluorescence intensity were examined 7 days after the first and the second passaging of iPSCs.Results iPSCs were observed to grow in a clonal manner under the inverted microscope.The iPSC markers,OCT4 and Nanog,were detected by immunofluorescence.With increasing concentrations of quantum dots,the fluorescence intensities representing the levels of OCT4 and Nanog in iPSCs were gradually elevated,with optimal levels of fluorescence observed at a concentration of 10 nmol/L of quantum dots.The fluorescent labeling of OCT4 and Nanog in iPSCs remained and weakened gradually till day 7 even after the second passage.Conclusions Quantum dots labeling could be used to track iPSCs in a dose-independent manner.The fluorescent signal from the quantum dots labeling the iPSCs lasts 2 weeks at least.

  11. Sushi-lautasastiasto : Asiakastyö

    OpenAIRE

    Ojala, Sini

    2016-01-01

    Opinnäytetyön aiheena oli valmistaa muokattu sushi-lautasastiasto asiakkaalle. Lähtökohtana oli aiemmassa muotoiluprojektissa suunnitellut lautaset: matala ruokalautanen ja keittolautanen. Niiden mallineet ja kipsimuotit oli valmistettu muotoiluprojektin aikana ja niitä käytettiin opinnäytetyössä. Sushi-lautasastiaston tilasi asiakas, joka oli nähnyt muotoiluprojektissa suunnitellut lautaset ja oli kiinnostunut niistä. Muotoiluprojektin lautasten pohjalta suunniteltiin ja valmistettiin so...

  12. Detection of Bacillus Anthracis Using Fluorescence Immunoassay with Quantum Dots Labels%荧光量子点免疫标记法检测炭疽芽孢杆菌

    Institute of Scientific and Technical Information of China (English)

    刘晓红; 罗金平; 田青; 刘春秀; 蔡新霞

    2011-01-01

    A method for detecting Bacillus anthracis (B. anthracis) was constructed with indirect immunofluorescence technique using quantum dots (QDs) as fluorescent probes. B. anthracis could be labeled with QDs selectively, that was proved by fluorescence microscope and F4500 spectrofluorometer. The laboratory-made system including biosensor and device was utilized as detection apparatus. A linear relationship of the fluorescence intensity and log total count of B. anthracis was obtained with correlation coefficient of 0. 9554 from 100 CFU/mL to 1 × 106 CFU/mL, and a low relative standard deviation of 2. 2%. By comparing the fluorescence intensity of B. anthracis and other bacillus, this method showed good specificity. Because of the simple operation, the detecting time is less (1 h) than traditional methods as well as quantitative detection, this method has potential prospect in monitoring B. anthracis and other biowarfare agents.%建立了荧光量子点标记-免疫分析技术联用检测炭疽芽孢杆菌的方法.通过抗原抗体反应,结合生物素与亲和素间的特异性相互作用,将QDs特异性标记在炭疽芽孢杆菌上,并利用荧光显微镜和荧光分光光度计进行了验证.采用实验室自制的便携式荧光检测系统对标记QDs的炭疽芽孢杆菌样品进行定量检测.结果表明,在炭疽芽孢杆菌浓度在100~1×106CFU/mL范围内,相对荧光强度与炭疽芽孢杆菌浓度呈良好的线性关系,相关系数R=0.9554,检测相对标准偏差为2.2%.通过与同菌属其它杆菌对比,证明本方法特异性良好.与传统方法相比,本方法操作简单,检测时间短(1 h),且能实现定量检测,在公共安全等方面有广泛的应用前景.

  13. Beyond Nigiri and Anisakiasis, The Tale of Sushi: History and Regulation

    OpenAIRE

    Feng, Cindy H.

    2006-01-01

    This paper is an exploration of the history of sushi consumption in the United States and how the ingredients of sushi are regulated. The paper delineates the course of sushi’s culinary history in Japan, and will attempt to present an overview on the incremental process by which sushi as a cuisine evolved from a humble street food with scarce recognition to an immensely sophisticated popular cuisine in Japan and America. After describing and analyzing the historical backgro...

  14. Tracking Quantum-Dot labeled neurotropic factors transport along primary neuronal axons in compartmental microfluidic chambers.

    Science.gov (United States)

    Gluska, Shani; Chein, Michael; Rotem, Nimrod; Ionescu, Ariel; Perlson, Eran

    2016-01-01

    Neurons are highly polarized cells, with very long axons. Neurotrophic factors like the neuronal growth factor (NGF) are secreted from neuronal targets to promote neuron survival and proper function. These neurotrophic factors must undergo retrograde axonal transport towards the cell body, wherein they initiate signaling pathways important for neurons' various functions and overall health. This process of long-distance axonal signaling is conducted by the dynein motor protein, which transmits signaling endosomes of ligand-receptor complexes retrogradely along microtubule tracks. Here we describe step by step the use of polydimethylsiloxane (PDMS) compartmentalized microfluidic chambers for tracking axonal transport of trophic factors, with a focus on labeled NGF. We describe in detail how to fabricate the molds, assemble the PDMS platform, plate neurons and image, as well as analyze NGF transport along the axon. This method is useful for studying molecular communication mechanisms within the neuron's different compartments as well as between the neuron and its diverse microenvironments, both in health and under pathological conditions.

  15. Sushi barcoding in the UK: another kettle of fish

    Directory of Open Access Journals (Sweden)

    Sara G. Vandamme

    2016-03-01

    Full Text Available Although the spread of sushi restaurants in the European Union and United States is a relatively new phenomenon, they have rapidly become among the most popular food services globally. Recent studies indicate that they can be associated with very high levels (>70% of fish species substitution. Based on indications that the European seafood retail sector may currently be under better control than its North American counterpart, here we investigated levels of seafood labelling accuracy in sushi bars and restaurants across England. We used the COI barcoding gene to screen samples of tuna, eel, and a variety of other products characterised by less visually distinctive ‘white flesh’. Moderate levels of substitution were found (10%, significantly lower than observed in North America, which lends support to the argument that public awareness, policy and governance of seafood labels is more effective in the European Union. Nevertheless, the results highlight that current labelling practice in UK restaurants lags behind the level of detail implemented in the retail sector, which hinders consumer choice, with potentially damaging economic, health and environmental consequences. Specifically, critically endangered species of tuna and eel continue to be sold without adequate information to consumers.

  16. Intestinal fluke infection as a result of eating sushi.

    Science.gov (United States)

    Adams, K O; Jungkind, D L; Bergquist, E J; Wirts, C W

    1986-11-01

    Severe diarrhea in a female outpatient was caused by an intestinal fluke, identified as Heterophyes heterophyes, a natural parasite of humans and domesticated and wild fish-eating mammals. This parasite is endemic in the Orient and the Middle East. A detailed case history revealed that the woman had never traveled outside the continental United States but became infected while eating raw fresh-water fish (sushi) that had been served at a local Japanese restaurant. The restaurant specialized in serving a great variety of fresh-water and salt-water fish that were flown in from the Orient and other parts of the world. The authors' findings indicate that a person does not have to travel to an endemic area to become infected with this organism.

  17. Hygienic-sanitary evaluation of sushi and sashimi sold in Messina and Catania, Italy

    Directory of Open Access Journals (Sweden)

    Daniele Muscolino

    2014-06-01

    Full Text Available Sushi and sashimi are traditional Japanese food, mostly consisting of raw seafood alone or in combination with rice. Eating sushi and sashimi has become popular in many countries even outside Japan. This food is not free from health risks such as ingestion of pathogenic bacteria or parasite. The aim of this study was to investigate on hygienic-sanitary quality of sushi and sashimi sold in the cities of Messina and Catania, Southern Italy. Fifty samples (38 sushi and 12 sashimi were analysed to determinate the aerobic mesophilic bacteria (AMB, psycrophilic bacteria (PB, Enterobacteriaceae, specific spoilage organisms (SSOs, Pseudomonas spp., coagulase-positive staphylococci, micrococci, Vibrio spp., Bacillus cereus, Salmonella spp. and Listeria monocytogenes. In sushi, AMB ranged from 5.00 to 8.18 log CFU/g, PB from 4.70 to 7.13 log CFU/g, Enterobacteriaceae from 1.41 to 6.67 log CFU/g, while SSOs and Pseudomonas spp. from 3.49 to 7.72 and from 3.36 to 8.00 log CFU/g, respectively. Micrococci ranged from 3.53 to 5.03 log CFU/g and coagulase positive staphylococci were found in 16 samples (2.00 to 3.60 log CFU/g. Bacillus cereus was found in 3 samples (1.70 to 4.00 log CFU/g, while Vibrio spp. was found in 15 of the sushi samples (1.70 to 3.70 log CFU/g. In sashimi, the AMB, PB and SSOs values were higher than 7.00 log CFU/g, Pseudomonas spp. and Enterobacteriaceae were from 6.00 to 8.00 log CFU/g, while Vibrio spp. were found in six samples with means of 2.00 log CFU/g. No Salmonella spp. and Listeria monocytogenes were detected in all sushi and sashimi samples.

  18. Hygienic-Sanitary Evaluation of Sushi and Sashimi Sold in Messina and Catania, Italy

    Science.gov (United States)

    Muscolino, Daniele; Giarratana, Filippo; Beninati, Chiara; Tornambene, Agata; Panebianco, Antonio

    2014-01-01

    Sushi and sashimi are traditional Japanese food, mostly consisting of raw seafood alone or in combination with rice. Eating sushi and sashimi has become popular in many countries even outside Japan. This food is not free from health risks such as ingestion of pathogenic bacteria or parasite. The aim of this study was to investigate on hygienic-sanitary quality of sushi and sashimi sold in the cities of Messina and Catania, Southern Italy. Fifty samples (38 sushi and 12 sashimi) were analysed to determinate the aerobic mesophilic bacteria (AMB), psycrophilic bacteria (PB), Enterobacteriaceae, specific spoilage organisms (SSOs), Pseudomonas spp., coagulase-positive staphylococci, micrococci, Vibrio spp., Bacillus cereus, Salmonella spp. and Listeria monocytogenes. In sushi, AMB ranged from 5.00 to 8.18 log CFU/g, PB from 4.70 to 7.13 log CFU/g, Enterobacteriaceae from 1.41 to 6.67 log CFU/g, while SSOs and Pseudomonas spp. from 3.49 to 7.72 and from 3.36 to 8.00 log CFU/g, respectively. Micrococci ranged from 3.53 to 5.03 log CFU/g and coagulase positive staphylococci were found in 16 samples (2.00 to 3.60 log CFU/g). Bacillus cereus was found in 3 samples (1.70 to 4.00 log CFU/g), while Vibrio spp. was found in 15 of the sushi samples (1.70 to 3.70 log CFU/g). In sashimi, the AMB, PB and SSOs values were higher than 7.00 log CFU/g, Pseudomonas spp. and Enterobacteriaceae were from 6.00 to 8.00 log CFU/g, while Vibrio spp. were found in six samples with means of 2.00 log CFU/g. No Salmonella spp. and Listeria monocytogenes were detected in all sushi and sashimi samples. PMID:27800343

  19. Application of the CALUXTM assay to the analysis of DXNs in a composite from Sushi samples and estimation of DXN intake from the Sushi items

    Energy Technology Data Exchange (ETDEWEB)

    Tagata, H.; Hiroyuki, K.; Toshio, N. [Japan Frozen Foods Inspection Corp., Yokohama (Japan); Masafumi, N.; Hisatoshi, Y.; Hiroshi, M. [Hiyoshi Corp., Shiga (Japan); Yoshiaki, A.; Tomoaki, T.; Kumiko, S. [National Inst. of Health Sciences, Tokyo (Japan); Kanako, N.; Masatake, T. [Jissen Women' s Univ., Tokyo (Japan)

    2004-09-15

    Introduction The CALUX assay, which reasonably and rapidly analyzes the amounts of dioxin-toxicity (CALUX TEQ), has been widely used as a method for screenings. The assay has been applied to environmental samples such as water, atmospheric air and soils, biological samples such as milk, blood and fat, and dietary samples such as fish and shellfish. In this study we have compared the CALUX assay with high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), in the analysis of DXN in sushi samples and estimated the DXN intake from the sushi meal. According to the total dietary study on the DXN carried out in the past 3 years in Japan, the DXN intake from fish and shellfish accounts for 74.4% of the total dietary DXN intake. As a sushi meal consists of various types of fish, shellfish and rice, we estimated the DXN intake from one meal of sushi using the DXN concentrations obtained by the HRGC/HRMS analysis.

  20. Gnathostomiasis in a patient who frequently consumes sushi.

    Science.gov (United States)

    Jarell, Abel D; Dans, Michael J; Elston, Dirk M; Mathison, Blaine A; Ruben, Beth S

    2011-12-01

    A 45-year-old woman presented for evaluation of a solitary pruritic nodule on the abdomen that suddenly appeared 3 weeks before. She was healthy without a significant medical history, travel history, exposures, medications, or pets. She reported that she consumed sushi at least weekly in the city of San Francisco. A punch biopsy revealed a superficial and deep perivascular and interstitial infiltrates consisting of lymphocytes, plasma cells, and many eosinophils. Most notably, there was a parasite centered in the reticular dermis with prominent lateral chords, a well-developed muscular esophagus, and an intestine that contained a brush border and multinucleate cells. Evaluation of these histological sections by the Centers for Disease Control and Prevention determined the parasite to be a nematode of the genus Gnathostoma. The patient underwent a systemic work-up for gnathostomiasis, including imaging, and no other abnormalities were found. She completed a 3-week course of albendazole and has remained asymptomatic since the biopsy of her abdominal lesion. Although gnathostomiasis is often a systemic illness, this patient did well with apparently only localized cutaneous disease. Gnathostomiasis should be considered in patients who present with nonspecific papules and nodules, especially when there is a history of frequent consumption of raw fish.

  1. Sushi delights and parasites: the risk of fishborne and foodborne parasitic zoonoses in Asia.

    Science.gov (United States)

    Nawa, Yukifumi; Hatz, Christoph; Blum, Johannes

    2005-11-01

    Because of the worldwide popularization of Japanese cuisine, the traditional Japanese fish dishes sushi and sashimi that are served in Japanese restaurants and sushi bars have been suspected of causing fishborne parasitic zoonoses, especially anisakiasis. In addition, an array of freshwater and brackish-water fish and wild animal meats, which are important sources of infection with zoonotic parasites, are served as sushi and sashimi in rural areas of Japan. Such fishborne and foodborne parasitic zoonoses are also endemic in many Asian countries that have related traditional cooking styles. Despite the recent increase in the number of travelers to areas where these zoonoses are endemic, travelers and even infectious disease specialists are unaware of the risk of infection associated with eating exotic ethnic dishes. The aim of this review is to provide practical background information regarding representative fishborne and foodborne parasitic zoonoses endemic in Asian countries.

  2. Sushi domains confer distinct trafficking profiles on GABAB receptors

    Science.gov (United States)

    Hannan, Saad; Wilkins, Megan E.; Smart, Trevor G.

    2012-01-01

    GABAB receptors mediate slow inhibitory neurotransmission in the brain and feature during excitatory synaptic plasticity, as well as various neurological conditions. These receptors are obligate heterodimers composed of GABABR1 and R2 subunits. The two predominant R1 isoforms differ by the presence of two complement control protein modules or Sushi domains (SDs) in the N terminus of R1a. By using live imaging, with an α-bungarotoxin-binding site (BBS) and fluorophore-linked bungarotoxin, we studied how R2 stabilizes R1b subunits at the cell surface. Heterodimerization with R2 reduced the rate of internalization of R1b, compared with R1b homomers. However, R1aR2 heteromers exhibited increased cell surface stability compared with R1bR2 receptors in hippocampal neurons, suggesting that for receptors containing the R1a subunit, the SDs play an additional role in the surface stability of GABAB receptors. Both SDs were necessary to increase the stability of R1aR2 because single deletions caused the receptors to be internalized at the same rate and extent as R1bR2 receptors. Consistent with these findings, a chimera formed from the metabotropic glutamate receptor (mGluR)2 and the SDs from R1a increased the surface stability of mGluR2. These results suggest a role for SDs in stabilizing cell surface receptors that could impart different pre- and postsynaptic trafficking itineraries on GABAB receptors, thereby contributing to their physiological and pathological roles. PMID:22778417

  3. A BRIEF HISTORY OF COUNTER AND SUSHI: the evolution of interdependent standards

    National Research Council Canada - National Science Library

    Oliver Pesch

    2015-01-01

    ... and the supporting Standardized Usage Statistics Harvesting (SUSHI) standard. 2000 - 2003: COUNTER formed The timeline shows 2002 as the year the COUNTER initiative was launched, but the work that led up to this had begun in earnest a few years before. Under the auspices of the Publishers and Libraries Solutions (PALS1) group, librarians and publishers had been ...

  4. Salt microspheres and potassium chloride usage for sodium reduction: Case study with sushi.

    Science.gov (United States)

    Đorđević, Đani; Buchtová, Hana; Macharáčková, Blanka

    2017-01-01

    The aim of the study was to estimate possibilities of salt substitutes usage in the preparation of two sushi types (nigiri and maki) prepared with different seafood (salmon: Salmo salar, tuna: Thunnus albacares, and shrimp: Pleoticus muelleri). Potassium chloride (Mary samples), Soda-Lo (hollowed microsphere of regular salt crystals), and regular salt (sodium chloride) were used in the experiment. Sushi samples (n = 1960) were evaluated by 40 trained panelists who noticed that maki shrimp samples prepared with Mary salt had higher bitterness (21.48 ± 28.01) in comparison with 2% sodium chloride (7.91 ± 8.80). The saltiness was lower in nigiri tuna prepared with Mary (49.59 ± 17.47) than 2% sodium chloride (61.11 ± 15.75). The study clearly showed the possibility of lowering sodium content in sushi meal with the usage of salt substitutes, with emphasis that Soda-Lo should be considered as a better option due to the retention of sensory properties in sushi samples prepared with this salt substitute.

  5. Sushi Lovers, Beware: Tapeworm Now Found in U.S. Salmon

    Science.gov (United States)

    ... his team has confirmed that the tapeworm is present in wild pink salmon from the Alaskan Pacific. The findings are published in the February issue of the CDC's journal Emerging Infectious Diseases . The risk of contracting the tapeworm from your sushi is low -- but it exists, said Dr. ...

  6. SusHi bento. Beyond NNLO and the heavy-top limit

    Energy Technology Data Exchange (ETDEWEB)

    Harlander, Robert V. [RWTH Aachen Univ. (Germany). Inst. for Theoretical Particle Physics and Cosmology; Liebler, Stefan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Mantler, Hendrik [Karlsruher Institut fuer Technologie (Germany). Inst. fuer Theoretische Physik; Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Experimentelle Kernphysik

    2016-05-15

    Version 1.6.0 of the code SusHi is presented. Concerning inclusive CP-even Higgs production in gluon fusion, the following new features with respect to previous versions have been implemented: expansion of the partonic cross section in the soft limit, i.e. around x=M{sup 2}{sub H}/s→1; N{sup 3}LO QCD corrections in terms of the soft expansion; top-quark mass suppressed terms through NNLO; matching to the cross section at x→0 through N{sup 3}LO. For CP-even and -odd scalars, an efficient evaluation of the renormalization-scale dependence is included, and effects of dimension-5 operators can be studied, which we demonstrate for the SM Higgs boson and for a CP-even scalar with a mass of 750 GeV. In addition, as a generalization of the previously available b anti b→H cross section, SusHi1.6.0 provides the cross section for charged and neutral Higgs production in the annihilation of arbitrary heavy quarks. At fixed order in perturbation theory, SusHi thus allows to obtain Higgs cross-section predictions in different models to the highest precision known today. For the SM Higgs boson of M{sub H}=125 GeV, SusHi yields 48.28 pb for the gluon-fusion cross section at the LHC at 13 TeV. Simultaneously, SusHi provides the renormalization-scale uncertainty of ±1.97 pb.

  7. Subtraction of unidirectionally encoded images for suppression of heavily isotropic objects (SUSHI) for selective visualization of peripheral nerves

    Energy Technology Data Exchange (ETDEWEB)

    Takahara, Taro; Kwee, Thomas C.; Hendrikse, Jeroen; Niwa, Tetsu; Mali, Willem P.T.M.; Luijten, Peter R. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Van Cauteren, Marc [Philips Healthcare, Asia Pacific, Tokyo (Japan); Koh, Dow-Mu [Royal Marsden Hospital, Department of Radiology, Sutton (United Kingdom)

    2011-02-15

    The aim of this study was to introduce and assess a new magnetic resonance (MR) technique for selective peripheral nerve imaging, called ''subtraction of unidirectionally encoded images for suppression of heavily isotropic objects'' (SUSHI). Six volunteers underwent diffusion-weighted MR neurography (DW-MRN) of the brachial plexus, and seven volunteers underwent DW-MRN of the sciatic, common peroneal, and tibial nerves at the level of the knee, at 1.5 T. DW-MRN images with SUSHI (DW-MRN{sub SUSHI}) and conventional DW-MRN images (DW-MRN{sub AP}) were displayed using a coronal maximum intensity projection and evaluated by two independent observers regarding signal suppression of lymph nodes, bone marrow, veins, and articular fluids and regarding signal intensity of nerves and ganglia, using five-point grading scales. Scores of DW-MRN{sub SUSHI} were compared to those of DW-MRN{sub AP} using Wilcoxon tests. Suppression of lymph nodes around the brachial plexus and suppression of articular fluids at the level of the knee at DW-MRN{sub SUSHI} was significantly better than that at DW-MRN{sub AP} (P < 0.05). However, overall signal intensity of brachial plexus nerves and ganglia at DW-MRN{sub SUSHI} was significantly lower than that at DW-MRN{sub AP} (P < 0.05). On the other hand, signal intensity of the sciatic, common peroneal, and tibial nerves at the level of the knee at DW-MRN{sub SUSHI} was judged as significantly better than that at DW-MRN{sub AP} (P < 0.05). The SUSHI technique allows more selective visualization of the sciatic, common peroneal, and tibial nerves at the level of the knee but is less useful for brachial plexus imaging because signal intensity of the brachial plexus nerves and ganglia can considerably be decreased. (orig.)

  8. Comparative conventional- and quantum dot-labelling strategies for LPS binding site detection in Arabidopsis thaliana mesophyll protoplasts

    Directory of Open Access Journals (Sweden)

    Londiwe Siphephise Mgcina

    2015-05-01

    Full Text Available Lipopolysaccharide (LPS from Gram-negative bacteria is recognized as a microbe-associated molecular pattern (MAMP and not only induces an innate immune response in plants, but also stimulates the development of characteristic defense responses. However, identification and characterization of a cell surface LPS-receptor/binding site, as described in mammals, remains elusive in plants. As an amphiphilic, macromolecular lipoglycan, intact LPS potentially contains three MAMP-active regions, represented by the O-polysaccharide chain, the core and the lipid A. Binding site studies with intact labelled LPS were conducted in Arabidopsis thaliana protoplasts and quantified using flow cytometry fluorescence changes. Qdots, which allow non-covalent, hydrophobic labelling were used as a novel strategy in this study and compared to covalent, hydrophilic labelling with Alexa 488. Affinity for LPS-binding sites was clearly demonstrated by concentration-, temperature- and time-dependent increases in protoplast fluorescence following treatment with the labelled LPS. Moreover, this induced fluorescence increase was convincingly reduced following pre-treatment with excess unlabeled LPS, thereby indicating reversibility of LPS binding. Inhibition of the binding process is also reported using endo- and exocytosis inhibitors. Here, we present evidence for the anticipated presence of LPS-specific binding sites in Arabidopsis protoplasts, and furthermore propose Qdots as a more sensitive LPS-labelling strategy in comparison to the conventional Alexa 488 hydrazide label for binding studies.

  9. Global Sushi: The Political Economy of the Mediterranian Bluefin Tuna Fishery in the Modern Era

    OpenAIRE

    Stefano B. Longo

    2015-01-01

    The bluefin tuna fishery in the Mediterranean has a long history of human interaction. In recent times, this fishery has become the central source of bluefin tuna for core nations, particularly Japan. This process was set off in large part by the growth of global fish markets, driven by the valuable sushi and sashimi market, and overfishing of other bluefin stocks in other parts of the world. The transformation of this fishery from an artisanal trap fishery to a globalized industrial fishery ...

  10. SusHi Bento: Beyond NNLO and the heavy-top limit

    CERN Document Server

    Harlander, Robert V; Mantler, Hendrik

    2016-01-01

    Version 1.6.0 of the code SusHi is presented. Concerning inclusive CP-even Higgs production in gluon fusion, the following new features with respect to previous versions have been implemented: expansion of the partonic cross section in the soft limit, i.e. around $x=M_H^2/\\hat{s}\\to 1$; N$^3$LO QCD corrections in terms of the soft expansion; top-quark mass suppressed terms through NNLO; matching to the cross section at $x\\to 0$ through N$^3$LO. For CP-even and -odd scalars, an efficient evaluation of the renormalization-scale dependence is included, and effects of dimension-5 operators can be studied, which we demonstrate for the SM Higgs boson and for a CP-even scalar with a mass of $750$ GeV. In addition, as a generalization of the previously available $b\\bar{b}\\to H$ cross section, SusHi 1.6.0 provides the cross section for charged and neutral Higgs production in the annihilation of arbitrary heavy quarks. At fixed order in perturbation theory, SusHi thus allows to obtain Higgs cross-section predictions in...

  11. The efficacy of X-ray does on murine norovirus-1 (MNV-1) in pure culture, half-shell oyster, salmon sushi, and tuna salad

    Science.gov (United States)

    In this investigation, we determined the efficacy of X-ray doses on reducing a human norovirus (HuNoV) surrogate [murine norovirus-1 (MNV-1)] in pure culture, half-shell oyster, salmon sushi and tuna salad. The pure culture (phosphate-buffer saline, pH 7.4), half-shell oyster, salmon sushi and tuna ...

  12. Oral allergy syndrome caused by raw fish in a Japanese sushi bar worker.

    Science.gov (United States)

    Sugita, Kazunari; Kabashima, Kenji; Nakashima, Daiki; Tokura, Yoshiki

    2007-06-01

    Oral allergy syndrome (OAS) is a complex of symptoms induced by exposure of the oral and pharyngeal mucosa to food allergens. A 23-year-old female presented in 2006 with oropharyngeal irritation and facial angioedema occurring within 15 min after eating raw fish. Her medical history was significant for mild atopic dermatitis and hand eczema. She had worked in a sushi bar since 2003. Clinical symptoms and positive prick-by-prick test to raw fish confirmed the diagnosis of OAS. It is likely that, our patient was sensitized by direct hand contact with raw fish.

  13. A B2C Digital Marketing Plan for the Sushi Restaurant Makuja

    OpenAIRE

    Maisuradze, Veronika

    2016-01-01

    This thesis was made for the sushi restaurant Makuja, which operates in Helsinki. The objective of the project was to create and partly implement a B2C digital marketing plan for the company: to make the first steps in building online presence, which would allow people to find Makuja on the Internet, get to know the restaurant better and interact with it. One of the main goals of online presence was to spread awareness and to gain followers, fans and customers. Five project tasks were set...

  14. Global Sushi: The Political Economy of the Mediterranian Bluefin Tuna Fishery in the Modern Era

    Directory of Open Access Journals (Sweden)

    Stefano B. Longo

    2015-08-01

    Full Text Available The bluefin tuna fishery in the Mediterranean has a long history of human interaction. In recent times, this fishery has become the central source of bluefin tuna for core nations, particularly Japan. This process was set off in large part by the growth of global fish markets, driven by the valuable sushi and sashimi market, and overfishing of other bluefin stocks in other parts of the world. The transformation of this fishery from an artisanal trap fishery to a globalized industrial fishery has had a number of social and environmental consequences. Based on in-depth fieldwork and historical research, this paper examines the political economy of the bluefin tuna fishery in the Mediterranean, with a focus on Sicily. It provides a descriptive history of the changing conditions in this fishery, paying special attention to the modern fishery. This research contributes to the discussions regarding the globalization and industrialization of agri-foodsystems and environmental degradation.

  15. The Real maccoyii: Identifying Tuna Sushi with DNA Barcodes – Contrasting Characteristic Attributes and Genetic Distances

    Science.gov (United States)

    Lowenstein, Jacob H.; Amato, George; Kolokotronis, Sergios-Orestis

    2009-01-01

    Background The use of DNA barcodes for the identification of described species is one of the least controversial and most promising applications of barcoding. There is no consensus, however, as to what constitutes an appropriate identification standard and most barcoding efforts simply attempt to pair a query sequence with reference sequences and deem identification successful if it falls within the bounds of some pre-established cutoffs using genetic distance. Since the Renaissance, however, most biological classification schemes have relied on the use of diagnostic characters to identify and place species. Methodology/Principal Findings Here we developed a cytochrome c oxidase subunit I character-based key for the identification of all tuna species of the genus Thunnus, and compared its performance with distance-based measures for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City) and Denver, Colorado. Both the character-based key and GenBank BLAST successfully identified 100% of the tuna samples, while the Barcode of Life Database (BOLD) as well as genetic distance thresholds, and neighbor-joining phylogenetic tree building performed poorly in terms of species identification. A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of “white tuna” were not albacore (T. alalunga), but escolar (Lepidocybium flavorunneum), a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus) or the critically endangered southern bluefin tuna (T. maccoyii), though nine restaurants that sold these species did not state these species on their menus. Conclusions/Significance The Convention on International Trade

  16. The real maccoyii: identifying tuna sushi with DNA barcodes--contrasting characteristic attributes and genetic distances.

    Directory of Open Access Journals (Sweden)

    Jacob H Lowenstein

    Full Text Available BACKGROUND: The use of DNA barcodes for the identification of described species is one of the least controversial and most promising applications of barcoding. There is no consensus, however, as to what constitutes an appropriate identification standard and most barcoding efforts simply attempt to pair a query sequence with reference sequences and deem identification successful if it falls within the bounds of some pre-established cutoffs using genetic distance. Since the Renaissance, however, most biological classification schemes have relied on the use of diagnostic characters to identify and place species. METHODOLOGY/PRINCIPAL FINDINGS: Here we developed a cytochrome c oxidase subunit I character-based key for the identification of all tuna species of the genus Thunnus, and compared its performance with distance-based measures for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City and Denver, Colorado. Both the character-based key and GenBank BLAST successfully identified 100% of the tuna samples, while the Barcode of Life Database (BOLD as well as genetic distance thresholds, and neighbor-joining phylogenetic tree building performed poorly in terms of species identification. A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of "white tuna" were not albacore (T. alalunga, but escolar (Lepidocybium flavorunneum, a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus or the critically endangered southern bluefin tuna (T. maccoyii, though nine restaurants that sold these species did not state these species on their menus. CONCLUSIONS/SIGNIFICANCE: The Convention on

  17. A Highly Selective and Sensitive Fluorescence Detection Method of Glyphosate Based on an Immune Reaction Strategy of Carbon Dot Labeled Antibody and Antigen Magnetic Beads.

    Science.gov (United States)

    Wang, Duo; Lin, Bixia; Cao, Yujuan; Guo, Manli; Yu, Ying

    2016-08-03

    A sensitive fluorescence detection method for glyphosate (GLY) was established based on immune reaction. First, carbon dot labeled antibodies (lgG-CDs) which were able to specifically identify glyphosate were prepared with the environmentally friendly carbon dots (CDs) and glyphosate antibody (lgG). lgG-CDs could be used to in situ visualize the distribution of glyphosate in plant tissues. In order to eliminate the effects of excess lgG-CDs on the determination of GLY, antigen magnetic beads Fe3O4-GLY based on magnetic nanoparticles Fe3O4 and glyphosate were constructed and utilized to couple with the excess lgG-CDs. After magnetic separation to remove antigen magnetic beads, there was a linear relationship between the fluorescence intensity of lgG-CDs and the logarithmic concentration of glyphosate in the range of 0.01-80 μg/mL with a detection limit of 8 ng/mL. The method was used for the detection of glyphosate in Pearl River water, tea, and soil samples with satisfactory recovery ratio between 87.4% and 103.7%.

  18. Pyrosequencing survey of the microbial diversity of 'narezushi', an archetype of modern Japanese sushi.

    Science.gov (United States)

    Koyanagi, T; Kiyohara, M; Matsui, H; Yamamoto, K; Kondo, T; Katayama, T; Kumagai, H

    2011-12-01

    This study aimed to analyse microbiota of the fermented food 'narezushi', an archetype of modern Japanese sushi. The pyrosequencing technique was used to analyse sequences of 16S ribosomal DNA contained in six narezushi products. The V1-V2 regions of the 16S ribosomal DNA were amplified from different narezushi products using PCR, and approximately 120,000 sequences were phylogenetically assigned at the genus level, using the Ribosomal Database Project classifier. In all samples, the microbial populations consisted of more than 90% Lactobacillales, mainly Lactobacillus or Pediococcus, reflecting their crucial role in narezushi fermentation. There were more than 700 operational taxonomy units in all samples, with Shannon-Wiener index varying from 1.69 to 2.60. The microbiota of all narezushi products were shown to consist largely of Lactobacillales populations. Interestingly, different species were found to be dominant in each product. This study provides an insight into the bacterial composition of fermented fish-based foods, which are consumed worldwide. Significant differences in the dominant species were observed between products, possibly because of the starter-free production process. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  19. Simultaneous Unbalanced Shared Local Oscillator Heterodyne Interferometry (SUSHI) for high SNR, minimally destructive dispersive detection of time-dependent atomic spins

    CERN Document Server

    Locke, Mary

    2013-01-01

    We demonstrate "Simultaneous Unbalanced Shared Local Oscillator Heterodyne Interferometry (SUSHI)," a new method for minimally destructive, high SNR dispersive detection of atomic spins. In SUSHI a dual-frequency probe laser interacts with atoms in one arm of a Mach-Zehnder interferometer, then beats against a bright local oscillator beam traversing the other arm, resulting in two simultaneous, independent heterodyne measurements of the atom-induced phase shift. Measurement noise due to mechanical disturbances of beam paths is strongly rejected by the technique of \\emph{active subtraction} in which anti-noise is actively written onto the local oscillator beam via an optical phase-locked-loop. In SUSHI, technical noise due to phase, amplitude, and frequency fluctuations of the various laser fields is strongly rejected (i) for any mean phase bias between the interferometer arms, (ii) without the use of piezo actuated mirrors, and (iii) without signal balancing. We experimentally demonstrate an ultra-low technic...

  20. DNA barcodes reveal species-specific mercury levels in tuna sushi that pose a health risk to consumers

    Science.gov (United States)

    Lowenstein, Jacob H.; Burger, Joanna; Jeitner, Christian W.; Amato, George; Kolokotronis, Sergios-Orestis; Gochfeld, Michael

    2010-01-01

    Excessive ingestion of mercury—a health hazard associated with consuming predatory fishes—damages neurological, sensory-motor and cardiovascular functioning. The mercury levels found in Bigeye Tuna (Thunnus obesus) and bluefin tuna species (Thunnus maccoyii, Thunnus orientalis, and Thunnus thynnus), exceed or approach levels permissible by Canada, the European Union, Japan, the US, and the World Health Organization. We used DNA barcodes to identify tuna sushi samples analysed for mercury and demonstrate that the ability to identify cryptic samples in the market place allows regulatory agencies to more accurately measure the risk faced by fish consumers and enact policies that better safeguard their health. PMID:20410032

  1. Estudio bacteriológico de sushi preparado y comercializado en San José, Costa Rica

    Directory of Open Access Journals (Sweden)

    Ana Patricia Madrigal

    2013-06-01

    Full Text Available Objetivo: Conocer la calidad bacteriológica de muestras de sushi expendidas en diferentes restaurantes de la provincia de San José en Costa Rica. Materiales y Método: Se analizaron 60 muestras de éste producto, a las cuales se les realizó mediante los procedimientos descritos en el Compendio de Métodos para el Examen Microbiológico de Alimentos, los siguientes análisis: recuento total aerobio mesófilo, número más probable de coliformes termotolerantes, fecales y E. coli, recuento de S. aureus y número más probable de B. cereus. Adicionalmente se investigó la presencia de patógenos relacionados con el sushi como: L. monocytogenes, Salmonella sp. y V parahaemolitycus. Resultados: El 6 (46% establecimientos presentaron positividad por E coli, aunque en poca cantidad (1 a 10 NMP/ g en promedio. Siete establecimientos (54% mostraron presencia de S. aureus, la mayoría en el orden de 10² UFC/ g. Adicionalmente, se logró aislar 2 cepas de B. cereus y2 de L. monocytogenes. No fue posible establecer la presencia de Salmonella sp. ni Vibrio parahaemolyticus en ninguna de las muestras evaluadas. Discusión: Según el Reglamento Técnico Centroamericano RTCA 67.04.50:08, en su sección 17.1 el 62% (8 de los establecimientos incluidos en el estudio incumplen con la norma establecida para este tipo de alimento. Esta no conformidad se da en la mayoría de los casos por la presencia de cantidades de S. aureus superiores a las 100 UFC/g.

  2. On Quoting Allusions Made by Sushi in His Poem Writing in Hangzhou%苏轼初次仕杭词用典分析

    Institute of Scientific and Technical Information of China (English)

    曾丹

    2013-01-01

    Sushi quoted allusions many times in his 36 poems which are written in Hangzhou .As far as the content of allusions are concerned , it indicated that Sushi cared about the life of common people .And his writing style has changed from the imperial court style to the folk one .As for the writing skills Sushi used , they embodied his ability to control the allusions .%苏轼初次外放到杭州所作的36首词,多处使用典故,且典故遍布经、史、子、集。从典故的内容来看,可以看出苏轼外表洒脱而心系百姓,并且已经开始由朝廷走向民间;从用典技巧来看,词中灵活地运用了多种用典手法,这无疑体现了苏轼娴熟的典故驾驭能力。

  3. Quantum

    CERN Document Server

    Al-Khalili, Jim

    2003-01-01

    In this lively look at quantum science, a physicist takes you on an entertaining and enlightening journey through the basics of subatomic physics. Along the way, he examines the paradox of quantum mechanics--beautifully mathematical in theory but confoundingly unpredictable in the real world. Marvel at the Dual Slit experiment as a tiny atom passes through two separate openings at the same time. Ponder the peculiar communication of quantum particles, which can remain in touch no matter how far apart. Join the genius jewel thief as he carries out a quantum measurement on a diamond without ever touching the object in question. Baffle yourself with the bizzareness of quantum tunneling, the equivalent of traveling partway up a hill, only to disappear then reappear traveling down the opposite side. With its clean, colorful layout and conversational tone, this text will hook you into the conundrum that is quantum mechanics.

  4. A small family of sushi-class retrotransposon-derived genes in mammals and their relation to genomic imprinting.

    Science.gov (United States)

    Youngson, Neil A; Kocialkowski, Sylvia; Peel, Nina; Ferguson-Smith, Anne C

    2005-10-01

    Ty3/gypsy retrotransposons are rare in mammalian genomes despite their abundance in invertebrate and other vertebrate classes. Here we identify a family of nine conserved mammalian genes with homology to Ty3/gypsy retrotransposons but which have lost their ability to autonomously retrotranspose. Of these, five map to the X chromosome while the remaining four are autosomal. Comparative phylogenetic analyses show them to have strongest homology to the sushi-ichi element from Fugu rubripes. Two of the autosomal gene members, Peg10 and Rtl1, are known to be imprinted, being expressed from the paternally inherited chromosome homologue. This suggests, consistent with the host-parasite response theory of the evolution of the imprinting mechanism, that parental-origin specific epigenetic control may be mediated by genomic "parasitic" elements such as these. Alternatively, these elements may preferentially integrate into regions that are differentially modified on the two homologous chromosomes such as imprinted domains and the X chromosome and acquire monoallelic expression. We assess the imprinting status of the remaining autosomal members of this family and show them to be biallelically expressed in embryo and placenta. Furthermore, the methylation status of Rtl1 was assayed throughout development and was found to resemble that of actively, silenced repetitive elements rather than imprinted sequences. This indicates that the ability to undergo genomic imprinting is not an inherent property of all members of this family of retroelements. Nonetheless, the conservation but functional divergence between the different members suggests that they have undergone positive selection and acquired distinct endogenous functions within their mammalian hosts.

  5. Bouillabaisse sushi fusion power

    CERN Multimedia

    2004-01-01

    "If avant-garde cuisine is any guide, Japanese-French fusion does not work all that well. And the interminable discussions over the International Thermonuclear Experimental Reactor (ITER) suggest that what is true of cooking is true of physics" (1 page)

  6. 苏轼与纳兰性德悼亡词比较%A Compared Study on the Memorial Poetry of Sushi and Nalanxingde

    Institute of Scientific and Technical Information of China (English)

    刘岩

    2013-01-01

    Sushi, a famous ci writer, is the first man to write memorial poem. Nalanxingde, a Chinese poet in Qing Dynasty. Although both of them wrote down a great deal of memorial poems, writing style is totally different. This paper aims at discussing the reason of the different creation features according to their personal experience.%宋代著名词人苏轼的一曲《江城子》是悼亡词真正意义上的开山之作,而清代纳兰性德则是文学史上写作悼亡词最多的作家。二者写的都是悼亡词,但风格却各有不同。本文旨在从二者的人生际遇上分析他们创作特色不同的原因。

  7. Quantum dots for multiplexed detection and characterisation of prostate cancer cells using a scanning near-field optical microscope.

    Directory of Open Access Journals (Sweden)

    Kelly-Ann D Walker

    Full Text Available In this study scanning near-field optical microscopy (SNOM has been utilised in conjunction with quantum dot labelling to interrogate the biomolecular composition of cell membranes. The technique overcomes the limits of optical diffraction found in standard fluorescence microscopy and also yields vital topographic information. The technique has been applied to investigate cell-cell adhesion in human epithelial cells. This has been realised through immunofluorescence labelling of the cell-cell adhesion protein E-cadherin. Moreover, a dual labelling protocol has been optimised to facilitate a comparative study of the adhesion mechanisms and the effect of aberrant adhesion protein expression in both healthy and cancerous epithelial cells. This study reports clear differences in the morphology and phenotype of healthy and cancerous cells. In healthy prostate epithelial cells (PNT2, E-cadherin was predominantly located around the cell periphery and within filopodial extensions. The presence of E-cadherin appeared to be enhanced when cell-cell contact was established. In contrast, examination of metastatic prostate adenocarcinoma cells (PC-3 revealed no E-cadherin labelling around the periphery of the cells. This lack of functional E-cadherin in PC-3 cells coincided with a markedly different morphology and PC-3 cells were not found to form close cell-cell associations with their neighbours. We have demonstrated that with a fully optimised sample preparation methodology, multiplexed quantum dot labelling in conjunction with SNOM imaging can be successfully applied to interrogate biomolecular localisation within delicate cellular membranes.

  8. Physical-chemical quality of fish used for making sushi and sashimi tuna and salmon marketed in Rio de Janeiro, BrazilQualidade físico-química do pescado utilizado na elaboração de sushis e sashimis de atum e salmão comercializados no município do Rio de Janeiro, Brasil

    Directory of Open Access Journals (Sweden)

    Bruna Leal Rodrigues

    2012-10-01

    Full Text Available This study aimed to determine the physical-chemical quality of fish used in a random sampling of 54 samples of sushi and sashimi tuna and salmon obtained in restaurants with the support of Sanitary Surveillance of the city of Rio de Janeiro from July to August 2011. The temperature were measured at the time of sampling. We carried out physical and chemical tests to determine pH, ammonia, H2S, total volatile bases (TVB, trimethylamine (TMA and histamine. All samples were exposed to inadequate temperature. Only one of the samples was found above the recommended pH value by law. Five were positive for ammonia and two positive results for H2S. The average results of TVB ranged between 9.43 and 12.37 mg N-BVT/100g and the amount of TMA ranged between 0.57 and 0.96 mg N-TMA/100g, being within the recommended standard. The histamine was found in five samples, ranging between 1 and 10 mg/100g. Considering the samples studied, seven (12,96% showed some abnormalities on the evaluated parameters. In conclusion, the consumption of sushi and sashimi can cause risk to consumer health. Therefore, we suggest that a continuous attention from the authorities should be held on this type of food due to their high perishability and risk to public health. O presente estudo objetivou determinar a qualidade físico-química do pescado utilizado em uma amostragem aleatória de 54 sushis e sashimis de atum e salmão obtidos em restaurantes com apoio da Vigilância Sanitária da cidade do Rio de Janeiro no período de julho a agosto de 2011. A temperatura foi mensurada no momento da coleta. Realizou-se provas físico-químicas de determinação de pH, amônia, H2S, bases voláteis totais (BVT, trimetilamina (TMA e histamina. Todas as amostras apresentavam-se expostas em temperatura inadequada. Apenas uma das amostras apresentou pH acima do limite preconizado pela legislação. Cinco apresentaram resultados positivos para amônia e duas resultados positivos para H2S. Os

  9. Views on Sushi on Ruzhou Road%蝉蜕尘埃外 蝶梦水云乡——汝州路上观苏轼

    Institute of Scientific and Technical Information of China (English)

    夏文先

    2012-01-01

    On the Ruzhou road, the changes of Sushi's thoughts and attitude towards life resulted from his deep introspection in Huangzhou after "Wu Tai Poetry Case". These changes can be seen through his impression on Lushan, his exploration of Shizhong Mount in Hukou, his visit of Ziyou in Yun Zhou,his meeting with Jiefu in Nanjing, even his asking for a field in Nanjing and his life in poverty in Changzhou. Sushi observed the social life based on reality and reasons and realized his dream of freedora,%汝州路上,苏轼思想、行为和人生态度的变化,无不是"乌台诗案"后黄州沉潜自省的结果。无论是庐山抒观感、湖口探石钟山,还是筠州访子由、金陵会介甫,甚至求田金陵和乞居常州等,皆可视为这种变化的外在显现。苏轼借助事物、事理观照社会、人生,从而实现了自我生命历程中由蛹到蝶的蜕变。

  10. Interpreting SUSHI-The Standardized Usage Statistics Harvesting Initiative Protocol%解读SUSHI——标准化的电子资源使用统计获取协议

    Institute of Scientific and Technical Information of China (English)

    杜莹琦; 郏琳

    2008-01-01

    SUSHI(The Standardized Usage Statistics Harvesting Initiative Protocol,标准化的电子资源使用统计获取协议)是基于WEB服务的SOAP(Simple Object Access Protocol)协议,为获取网络电子资源的用户使用统计报告提供自动化的数据交换方法.论文从基础、技术内涵和实际应用等方面对SUSHI进行了深入分析.

  11. DNA nanosensor based on biocompatible graphene quantum dots and carbon nanotubes.

    Science.gov (United States)

    Qian, Zhao Sheng; Shan, Xiao Yue; Chai, Lu Jing; Ma, Juan Juan; Chen, Jian Rong; Feng, Hui

    2014-10-15

    An ultrasensitive nanosensor based on fluorescence resonance energy transfer (FRET) between biocompatible graphene quantum dots and carbon nanotubes for DNA detection was reported. We take advantage of good biocompatibility and strong fluorescence of graphene quantum dots, base pairing specificity of DNA and unique fluorescence resonance energy transfer between graphene quantum dots and carbon nanotubes to achieve the analysis of low concentrations of DNA. Graphene quantum dots with high quantum yield up to 0.20 were prepared and served as the fluorophore of DNA probe. FRET process between graphene quantum dots-labeled probe and oxidized carbon nanotubes is easily achieved due to their efficient self-assembly through specific π-π interaction. This nanosensor can distinguish complementary and mismatched nucleic acid sequences with high sensitivity and good reproducibility. The detection method based on this nanosensor possesses a broad linear span of up to 133.0 nM and ultralow detection limit of 0.4 nM. The constructed nanosensor is expected to be highly biocompatible because of all its components with excellent biocompatibility.

  12. Capillary electrophoresis for the characterization of quantum dots after non-selective or selective bioconjugation with antibodies for immunoassay

    Directory of Open Access Journals (Sweden)

    Lai Edward PC

    2008-10-01

    Full Text Available Abstract Capillary electrophoresis coupled with laser-induced fluorescence was used for the characterization of quantum dots and their conjugates to biological molecules. The CE-LIF was laboratory-built and capable of injection (hydrodynamic and electrokinetic from sample volumes as low as 4 μL via the use of a modified micro-fluidic chip platform. Commercially available quantum dots were bioconjugated to proteins and immunoglobulins through the use of established techniques (non-selective and selective. Non-selective techniques involved the use of EDCHCl/sulfo-NHS for the conjugation of BSA and myoglobin to carboxylic acid-functionalized quantum dots. Selective techniques involved 1 the use of heterobifunctional crosslinker, sulfo-SMCC, for the conjugation of partially reduced IgG to amine-functionalized quantum dots, and 2 the conjugation of periodate-oxidized IgGs to hydrazide-functionalized quantum dots. The migration times of these conjugates were determined in comparison to their non-conjugated QD relatives based upon their charge-to-size ratio values. The performance of capillary electrophoresis in characterizing immunoconjugates of quantum dot-labeled IgGs was also evaluated. Together, both QDs and CE-LIF can be applied as a sensitive technique for the detection of biological molecules. This work will contribute to the advancements in applying nanotechnology for molecular diagnosis in medical field.

  13. A Novel Quantum Dots-Based Point of Care Test for Syphilis

    Science.gov (United States)

    Yang, Hao; Li, Ding; He, Rong; Guo, Qin; Wang, Kan; Zhang, Xueqing; Huang, Peng; Cui, Daxiang

    2010-05-01

    One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots-based method reached up to 100% (95% confidence interval [CI], 91-100%), while those of the colloidal gold-based method were 82% (95% CI, 68-91%) and 100% (95% CI, 91-100%), respectively. In addition, the naked-eye detection limit of quantum dot-based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold-based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening.

  14. 延续历史文脉凸显苏轼文化——云龙湖风景区文化资源现状及提升对策%Continue historical tradition e and signify Sushi culture --Current status and strategy for improvement of cultural resources in the scenic area of Yunlong Lake

    Institute of Scientific and Technical Information of China (English)

    李云岘

    2009-01-01

    To adequately demonstrate the cultural connotation of a city and appropriately explore new municipal scenic spots plays an extremely significant role in carrying forward the spirit of the city, upgrading the quality and promoting the harmony,the unification and the development of the municipal scenic spots even the entire city. This essay systematically analyses the cultural landscape resources,objectively researches and puts forward the implementing optimistic strategy of protection and utilization and focusing on upgrading the cultural connotation of the scenic spots. Especially by investigating the remains and utilization of the Sushi Culture in Yunlong Lake scenic spots,this essay proposes the idea of extending the history context and advocating the Sushi Culture and initiates a new way of carrying forward and inheriting the municipal culture meanwhile.

  15. Quantum dot coating of baculoviral vectors enables visualization of transduced cells and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ying; Lo, Seong Loong [Institute of Bioengineering and Nanotechnology, Singapore (Singapore); Zheng, Yuangang [Institute of Materials Research and Engineering, Singapore (Singapore); Lam, Dang Hoang [Institute of Bioengineering and Nanotechnology, Singapore (Singapore); Department of Biological Sciences, National University of Singapore, Singapore (Singapore); Wu, Chunxiao [Institute of Bioengineering and Nanotechnology, Singapore (Singapore); Han, Ming Yong [Institute of Materials Research and Engineering, Singapore (Singapore); Wang, Shu, E-mail: dbsws@nus.edu.sg [Institute of Bioengineering and Nanotechnology, Singapore (Singapore); Department of Biological Sciences, National University of Singapore, Singapore (Singapore)

    2013-04-26

    Highlights: •The use of quantum dot (QD)-labeled viral vectors for in vivo imaging is not well investigated. •A new method to label enveloped baculovirus with glutathione-capped CdTe QDs is developed. •The labeling enables the identification of transduced, cultured cells based on fluorescence. •The labeling also allows evaluation of viral transduction in a real-time manner in living mice. •The method has the potential to assess viral vector-based gene therapy protocols in future. -- Abstract: Imaging of transduced cells and tissues is valuable in developing gene transfer vectors and evaluating gene therapy efficacy. We report here a simple method to use bright and photostable quantum dots to label baculovirus, an emerging gene therapy vector. The labeling was achieved through the non-covalent interaction of glutathione-capped CdTe quantum dots with the virus envelope, without the use of chemical conjugation. The quantum dot labeling was nondestructive to viral transduction function and enabled the identification of baculoviral vector-transduced, living cells based on red fluorescence. When the labeled baculoviral vectors were injected intravenously or intraventricularly for in vivo delivery of a transgene into mice, quantum dot fluorescence signals allow us monitor whether or not the injected tissues were transduced. More importantly, using a dual-color whole-body imaging technology, we demonstrated that in vivo viral transduction could be evaluated in a real-time manner in living mice. Thus, our method of labeling a read-to-use gene delivery vector with quantum dots could be useful towards the improvement of vector design and will have the potential to assess baculovirus-based gene therapy protocols in future.

  16. Quantum computing

    OpenAIRE

    Li, Shu-Shen; Long, Gui-lu; Bai, Feng-Shan; Feng, Song-Lin; Zheng, Hou-Zhi

    2001-01-01

    Quantum computing is a quickly growing research field. This article introduces the basic concepts of quantum computing, recent developments in quantum searching, and decoherence in a possible quantum dot realization.

  17. Quantum Distinction: Quantum Distinctiones!

    OpenAIRE

    Zeps, Dainis

    2009-01-01

    10 pages; How many distinctions, in Latin, quantum distinctiones. We suggest approach of anthropic principle based on anthropic reference system which should be applied equally both in theoretical physics and in mathematics. We come to principle that within reference system of life subject of mathematics (that of thinking) should be equated with subject of physics (that of nature). For this reason we enter notions of series of distinctions, quantum distinction, and argue that quantum distinct...

  18. Quantum stochastics

    CERN Document Server

    Chang, Mou-Hsiung

    2015-01-01

    The classical probability theory initiated by Kolmogorov and its quantum counterpart, pioneered by von Neumann, were created at about the same time in the 1930s, but development of the quantum theory has trailed far behind. Although highly appealing, the quantum theory has a steep learning curve, requiring tools from both probability and analysis and a facility for combining the two viewpoints. This book is a systematic, self-contained account of the core of quantum probability and quantum stochastic processes for graduate students and researchers. The only assumed background is knowledge of the basic theory of Hilbert spaces, bounded linear operators, and classical Markov processes. From there, the book introduces additional tools from analysis, and then builds the quantum probability framework needed to support applications to quantum control and quantum information and communication. These include quantum noise, quantum stochastic calculus, stochastic quantum differential equations, quantum Markov semigrou...

  19. Quantum Computing

    CERN Document Server

    Steane, A M

    1998-01-01

    The subject of quantum computing brings together ideas from classical information theory, computer science, and quantum physics. This review aims to summarise not just quantum computing, but the whole subject of quantum information theory. It turns out that information theory and quantum mechanics fit together very well. In order to explain their relationship, the review begins with an introduction to classical information theory and computer science, including Shannon's theorem, error correcting codes, Turing machines and computational complexity. The principles of quantum mechanics are then outlined, and the EPR experiment described. The EPR-Bell correlations, and quantum entanglement in general, form the essential new ingredient which distinguishes quantum from classical information theory, and, arguably, quantum from classical physics. Basic quantum information ideas are described, including key distribution, teleportation, data compression, quantum error correction, the universal quantum computer and qua...

  20. Quantum Blobs

    OpenAIRE

    Gosson, Maurice A. de

    2012-01-01

    Quantum blobs are the smallest phase space units of phase space compatible with the uncertainty principle of quantum mechanics and having the symplectic group as group of symmetries. Quantum blobs are in a bijective correspondence with the squeezed coherent states from standard quantum mechanics, of which they are a phase space picture. This allows us to propose a substitute for phase space in quantum mechanics. We study the relationship between quantum blobs with a certain class of level set...

  1. Nonlinear Dynamics In Quantum Physics -- Quantum Chaos and Quantum Instantons

    OpenAIRE

    Kröger, H.

    2003-01-01

    We discuss the recently proposed quantum action - its interpretation, its motivation, its mathematical properties and its use in physics: quantum mechanical tunneling, quantum instantons and quantum chaos.

  2. Nonlinear Dynamics In Quantum Physics -- Quantum Chaos and Quantum Instantons

    OpenAIRE

    Kröger, H.

    2003-01-01

    We discuss the recently proposed quantum action - its interpretation, its motivation, its mathematical properties and its use in physics: quantum mechanical tunneling, quantum instantons and quantum chaos.

  3. Quantum radar

    CERN Document Server

    Lanzagorta, Marco

    2011-01-01

    This book offers a concise review of quantum radar theory. Our approach is pedagogical, making emphasis on the physics behind the operation of a hypothetical quantum radar. We concentrate our discussion on the two major models proposed to date: interferometric quantum radar and quantum illumination. In addition, this book offers some new results, including an analytical study of quantum interferometry in the X-band radar region with a variety of atmospheric conditions, a derivation of a quantum radar equation, and a discussion of quantum radar jamming.This book assumes the reader is familiar w

  4. Quantum Blobs

    CERN Document Server

    de Gosson, Maurice A

    2011-01-01

    Quantum blobs are the smallest phase space units of phase space compatible with the uncertainty principle of quantum mechanics and having the symplectic group as group of symmetries. Quantum blobs are in a bijective correspondence with the squeezed coherent states from standard quantum mechanics, of which they are a phase space picture. This allows us to propose a substitute for phase space in quantum mechanics. We study the relationship between quantum blobs with a certain class of level sets defined by Fermi for the purpose of representing geometrically quantum states.

  5. Quantum Malware

    CERN Document Server

    Wu, L A; Wu, Lian-Ao; Lidar, Daniel

    2005-01-01

    Quantum computation and communication offer unprecedented advantages compared to classical information processing. Currently, quantum communication is moving from laboratory prototypes into real-life applications. When quantum communication networks become more widespread it is likely that they will be subject to attacks by hackers, virus makers, and other malicious intruders. Here we introduce the concept of "quantum malware" to describe such human-made intrusions. We offer a simple solution for storage of quantum information in a manner which protects quantum networks from quantum malware.

  6. Quantum cloning

    OpenAIRE

    Scarani, Valerio; Iblisdir, Sofyan; Gisin, Nicolas; Acin, Antonio

    2005-01-01

    The impossibility of perfectly copying (or cloning) an arbitrary quantum state is one of the basic rules governing the physics of quantum systems. The processes that perform the optimal approximate cloning have been found in many cases. These "quantum cloning machines" are important tools for studying a wide variety of tasks, e.g. state estimation and eavesdropping on quantum cryptography. This paper provides a comprehensive review of quantum cloning machines (both for discrete-dimensional an...

  7. Quantum CPU and Quantum Algorithm

    OpenAIRE

    Wang, An Min

    1999-01-01

    Making use of an universal quantum network -- QCPU proposed by me\\upcite{My1}, it is obtained that the whole quantum network which can implement some the known quantum algorithms including Deutsch algorithm, quantum Fourier transformation, Shor's algorithm and Grover's algorithm.

  8. Quantum Computer Games: Quantum Minesweeper

    Science.gov (United States)

    Gordon, Michal; Gordon, Goren

    2010-01-01

    The computer game of quantum minesweeper is introduced as a quantum extension of the well-known classical minesweeper. Its main objective is to teach the unique concepts of quantum mechanics in a fun way. Quantum minesweeper demonstrates the effects of superposition, entanglement and their non-local characteristics. While in the classical…

  9. Quantum Computer Games: Quantum Minesweeper

    Science.gov (United States)

    Gordon, Michal; Gordon, Goren

    2010-01-01

    The computer game of quantum minesweeper is introduced as a quantum extension of the well-known classical minesweeper. Its main objective is to teach the unique concepts of quantum mechanics in a fun way. Quantum minesweeper demonstrates the effects of superposition, entanglement and their non-local characteristics. While in the classical…

  10. Quantum memristors

    Science.gov (United States)

    Pfeiffer, P.; Egusquiza, I. L.; di Ventra, M.; Sanz, M.; Solano, E.

    2016-07-01

    Technology based on memristors, resistors with memory whose resistance depends on the history of the crossing charges, has lately enhanced the classical paradigm of computation with neuromorphic architectures. However, in contrast to the known quantized models of passive circuit elements, such as inductors, capacitors or resistors, the design and realization of a quantum memristor is still missing. Here, we introduce the concept of a quantum memristor as a quantum dissipative device, whose decoherence mechanism is controlled by a continuous-measurement feedback scheme, which accounts for the memory. Indeed, we provide numerical simulations showing that memory effects actually persist in the quantum regime. Our quantization method, specifically designed for superconducting circuits, may be extended to other quantum platforms, allowing for memristor-type constructions in different quantum technologies. The proposed quantum memristor is then a building block for neuromorphic quantum computation and quantum simulations of non-Markovian systems.

  11. Quantum trajectories

    CERN Document Server

    Chattaraj, Pratim Kumar

    2010-01-01

    The application of quantum mechanics to many-particle systems has been an active area of research in recent years as researchers have looked for ways to tackle difficult problems in this area. The quantum trajectory method provides an efficient computational technique for solving both stationary and time-evolving states, encompassing a large area of quantum mechanics. Quantum Trajectories brings the expertise of an international panel of experts who focus on the epistemological significance of quantum mechanics through the quantum theory of motion.Emphasizing a classical interpretation of quan

  12. Quantum robots and quantum computers

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.

    1998-07-01

    Validation of a presumably universal theory, such as quantum mechanics, requires a quantum mechanical description of systems that carry out theoretical calculations and systems that carry out experiments. The description of quantum computers is under active development. No description of systems to carry out experiments has been given. A small step in this direction is taken here by giving a description of quantum robots as mobile systems with on board quantum computers that interact with different environments. Some properties of these systems are discussed. A specific model based on the literature descriptions of quantum Turing machines is presented.

  13. Quantum Darwinism

    Energy Technology Data Exchange (ETDEWEB)

    Zurek, Wojciech H [Los Alamos National Laboratory

    2008-01-01

    Quantum Darwinism - proliferation, in the environment, of multiple records of selected states of the system (its information-theoretic progeny) - explains how quantum fragility of individual state can lead to classical robustness of their multitude.

  14. Quantum music

    CERN Document Server

    Putz, Volkmar

    2015-01-01

    We consider ways of conceptualizing, rendering and perceiving quantum music, and quantum art in general. Thereby we give particular emphasis to its non-classical aspects, such as coherent superposition and entanglement.

  15. Quantum Abacus

    CERN Document Server

    Cheon, T

    2004-01-01

    We show that the U(2) family of point interactions on a line can be utilized to provide the U(2) family of qubit operations for quantum information processing. Qubits are realized as localized states in either side of the point interaction which represents a controllable gate. The manipulation of qubits proceeds in a manner analogous to the operation of an abacus. Keywords: quantum computation, quantum contact interaction, quantum wire

  16. Quantum Econophysics

    OpenAIRE

    Esteban Guevara

    2006-01-01

    The relationships between game theory and quantum mechanics let us propose certain quantization relationships through which we could describe and understand not only quantum but also classical, evolutionary and the biological systems that were described before through the replicator dynamics. Quantum mechanics could be used to explain more correctly biological and economical processes and even it could encloses theories like games and evolutionary dynamics. This could make quantum mechanics a...

  17. Quantum Nanomechanics

    OpenAIRE

    2008-01-01

    Quantum Nanomechanics is the emerging field which pertains to the mechanical behavior of nanoscale systems in the quantum domain. Unlike the conventional studies of vibration of molecules and phonons in solids, quantum nanomechanics is defined as the quantum behavior of the entire mechanical structure, including all of its constituents--the atoms, the molecules, the ions, the electrons as well as other excitations. The relevant degrees of freedom of the system are described by macroscopic var...

  18. Quantum cryptography

    NARCIS (Netherlands)

    Fehr, S.

    2010-01-01

    Quantum cryptography makes use of the quantum-mechanical behavior of nature for the design and analysis of cryptographic schemes. Optimally (but not always), quantum cryptography allows for the design of cryptographic schemes whose security is guaranteed solely by the laws of nature. This is in shar

  19. Quantum Computing for Quantum Chemistry

    Science.gov (United States)

    2010-09-01

    This three-year project consisted on the development and application of quantum computer algorithms for chemical applications. In particular, we developed algorithms for chemical reaction dynamics, electronic structure and protein folding. The first quantum computing for

  20. Quantum Operations as Quantum States

    CERN Document Server

    Arrighi, P; Arrighi, Pablo; Patricot, Christophe

    2004-01-01

    In this article we formalize the correspondence between quantum states and quantum operations, and harness its consequences. This correspondence was already implicit in Choi's proof of the operator sum representation of Completely Positive-preserving linear maps; we go further and show that all of the important theorems concerning quantum operations can be derived as simple corollaries of those concerning quantum states. As we do so the discussion first provides an elegant and original review of the main features of quantum operations. Next (in the second half of the paper) we search for more results to arise from the correspondence. Thus we propose a factorizability condition and an extremal trace-preservedness condition for quantum operations, give two novel Schmidt-type decompositions of bipartite pure states and two interesting composition laws for which the set of quantum operations and quantum states remain stable. The latter enables us to define a group structure upon the set of totally entangled state...

  1. Quantum memory in quantum cryptography

    CERN Document Server

    Mor, T

    1999-01-01

    [Shortened abstract:] This thesis investigates the importance of quantum memory in quantum cryptography, concentrating on quantum key distribution schemes. In the hands of an eavesdropper -- a quantum memory is a powerful tool, putting in question the security of quantum cryptography; Classical privacy amplification techniques, used to prove security against less powerful eavesdroppers, might not be effective when the eavesdropper can keep quantum states for a long time. In this work we suggest a possible direction for approaching this problem. We define strong attacks of this type, and show security against them, suggesting that quantum cryptography is secure. We start with a complete analysis regarding the information about a parity bit (since parity bits are used for privacy amplification). We use the results regarding the information on parity bits to prove security against very strong eavesdropping attacks, which uses quantum memories and all classical data (including error correction codes) to attack th...

  2. Quantum Darwinism

    Science.gov (United States)

    Zurek, Wojciech Hubert

    2009-03-01

    Quantum Darwinism describes the proliferation, in the environment, of multiple records of selected states of a quantum system. It explains how the quantum fragility of a state of a single quantum system can lead to the classical robustness of states in their correlated multitude; shows how effective `wave-packet collapse' arises as a result of the proliferation throughout the environment of imprints of the state of the system; and provides a framework for the derivation of Born's rule, which relates the probabilities of detecting states to their amplitudes. Taken together, these three advances mark considerable progress towards settling the quantum measurement problem.

  3. Quantum entanglement and quantum operation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It is a simple introduction to quantum entanglement and quantum operations. The authors focus on some applications of quantum entanglement and relations between two-qubit entangled states and unitary operations. It includes remote state preparation by using any pure entangled states, nonlocal operation implementation using entangled states, entanglement capacity of two-qubit gates and two-qubit gates construction.

  4. Quantum entanglement

    CERN Document Server

    Horodecki, R; Horodecki, M; Horodecki, K; Horodecki, Ryszard; Horodecki, Pawel; Horodecki, Michal; Horodecki, Karol

    2007-01-01

    All our former experience with application of quantum theory seems to say: {\\it what is predicted by quantum formalism must occur in laboratory}. But the essence of quantum formalism - entanglement, recognized by Einstein, Podolsky, Rosen and Schr\\"odinger - waited over 70 years to enter to laboratories as a new resource as real as energy. This holistic property of compound quantum systems, which involves nonclassical correlations between subsystems, is a potential for many quantum processes, including ``canonical'' ones: quantum cryptography, quantum teleportation and dense coding. However, it appeared that this new resource is very complex and difficult to detect. Being usually fragile to environment, it is robust against conceptual and mathematical tools, the task of which is to decipher its rich structure. This article reviews basic aspects of entanglement including its characterization, detection, distillation and quantifying. In particular, the authors discuss various manifestations of entanglement via ...

  5. Quantum relations

    CERN Document Server

    Weaver, Nik

    2010-01-01

    We define a "quantum relation" on a von Neumann algebra M \\subset B(H) to be a weak* closed operator bimodule over its commutant M'. Although this definition is framed in terms of a particular representation of M, it is effectively representation independent. Quantum relations on l^\\infty(X) exactly correspond to subsets of X^2, i.e., relations on X. There is also a good definition of a "measurable relation" on a measure space, to which quantum relations partially reduce in the general abelian case. By analogy with the classical setting, we can identify structures such as quantum equivalence relations, quantum partial orders, and quantum graphs, and we can generalize Arveson's fundamental work on weak* closed operator algebras containing a masa to these cases. We are also able to intrinsically characterize the quantum relations on M in terms of families of projections in M \\otimes B(l^2).

  6. Quantum Games and Quantum Discord

    CERN Document Server

    Nawaz, Ahmad

    2010-01-01

    We quantize prisoners dilemma and chicken game by our generalized quantization scheme to explore the role of quantum discord in quantum games. In order to establish this connection we use Werner-like state as an initial state of the game. In this quantization scheme measurement can be performed in entangled as well as in product basis. For the measurement in entangled basis the dilemma in both the games can be resolved by separable states with non-zero quantum discord. Similarly for product basis measurement the payoffs are quantum mechanical only for nonzero values of quantum discord.

  7. Quantum cryptography

    CERN Document Server

    Gilbert, Gerald; Hamrick, Michael

    2013-01-01

    This book provides a detailed account of the theory and practice of quantum cryptography. Suitable as the basis for a course in the subject at the graduate level, it crosses the disciplines of physics, mathematics, computer science and engineering. The theoretical and experimental aspects of the subject are derived from first principles, and attention is devoted to the practical development of realistic quantum communications systems. The book also includes a comprehensive analysis of practical quantum cryptography systems implemented in actual physical environments via either free-space or fiber-optic cable quantum channels. This book will be a valuable resource for graduate students, as well as professional scientists and engineers, who desire an introduction to the field that will enable them to undertake research in quantum cryptography. It will also be a useful reference for researchers who are already active in the field, and for academic faculty members who are teaching courses in quantum information s...

  8. Quantum Decoys

    CERN Document Server

    Arrighi, P

    2003-01-01

    Alice communicates with words drawn uniformly amongst $\\{\\ket{j}\\}_{j=1..n}$, the canonical orthonormal basis. Sometimes however Alice interleaves quantum decoys $\\{\\frac{\\ket{j}+i\\ket{k}}{\\sqrt{2}}\\}$ between her messages. Such pairwise superpositions of possible words cannot be distinguished from the message words. Thus as malevolent Eve observes the quantum channel, she runs the risk of damaging the superpositions (by causing a collapse). At the receiving end honest Bob, whom we assume is warned of the quantum decoys' distribution, checks upon their integrity with a measurement. The present work establishes, in the case of individual attacks, the tradeoff between Eve's information gain (her chances, if a message word was sent, of guessing which) and the disturbance she induces (Bob's chances, if a quantum decoy was sent, to detect tampering). Besides secure channel protocols, quantum decoys seem a powerful primitive for constructing n-dimensional quantum cryptographic applications. Moreover the methods emp...

  9. Quantum measurement

    CERN Document Server

    Busch, Paul; Pellonpää, Juha-Pekka; Ylinen, Kari

    2016-01-01

    This is a book about the Hilbert space formulation of quantum mechanics and its measurement theory. It contains a synopsis of what became of the Mathematical Foundations of Quantum Mechanics since von Neumann’s classic treatise with this title. Fundamental non-classical features of quantum mechanics—indeterminacy and incompatibility of observables, unavoidable measurement disturbance, entanglement, nonlocality—are explicated and analysed using the tools of operational quantum theory. The book is divided into four parts: 1. Mathematics provides a systematic exposition of the Hilbert space and operator theoretic tools and relevant measure and integration theory leading to the Naimark and Stinespring dilation theorems; 2. Elements develops the basic concepts of quantum mechanics and measurement theory with a focus on the notion of approximate joint measurability; 3. Realisations offers in-depth studies of the fundamental observables of quantum mechanics and some of their measurement implementations; and 4....

  10. Quantum Computers

    Science.gov (United States)

    2010-03-04

    efficient or less costly than their classical counterparts. A large-scale quantum computer is certainly an extremely ambi- tious goal, appearing to us...outperform the largest classical supercomputers in solving some specific problems important for data encryption. In the long term, another application...which the quantum computer depends, causing the quantum mechanically destructive process known as decoherence . Decoherence comes in several forms

  11. Quantum cryptography

    CERN Document Server

    Hughes, R J; Dyer, P L; Luther, G G; Morgan, G L; Schauer, M M; Hughes, Richard J; Dyer, P; Luther, G G; Morgan, G L; Schauer, M

    1995-01-01

    Quantum cryptography is a new method for secret communications offering the ultimate security assurance of the inviolability of a Law of Nature. In this paper we shall describe the theory of quantum cryptography, its potential relevance and the development of a prototype system at Los Alamos, which utilises the phenomenon of single-photon interference to perform quantum cryptography over an optical fiber communications link.

  12. Quantum information

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, P

    1998-03-01

    There is more to information than a string of ones and zeroes the ability of ''quantum bits'' to be in two states at the same time could revolutionize information technology. In the mid-1930s two influential but seemingly unrelated papers were published. In 1935 Einstein, Podolsky and Rosen proposed the famous EPR paradox that has come to symbolize the mysteries of quantum mechanics. Two years later, Alan Turing introduced the universal Turing machine in an enigmatically titled paper, On computable numbers, and laid the foundations of the computer industry one of the biggest industries in the world today. Although quantum physics is essential to understand the operation of transistors and other solid-state devices in computers, computation itself has remained a resolutely classical process. Indeed it seems only natural that computation and quantum theory should be kept as far apart as possible surely the uncertainty associated with quantum theory is anathema to the reliability expected from computers? Wrong. In 1985 David Deutsch introduced the universal quantum computer and showed that quantum theory can actually allow computers to do more rather than less. The ability of particles to be in a superposition of more than one quantum state naturally introduces a form of parallelism that can, in principle, perform some traditional computing tasks faster than is possible with classical computers. Moreover, quantum computers are capable of other tasks that are not conceivable with their classical counterparts. Similar breakthroughs in cryptography and communication followed. (author)

  13. Quantum Networks for Generating Arbitrary Quantum States

    OpenAIRE

    Kaye, Phillip; Mosca, Michele

    2004-01-01

    Quantum protocols often require the generation of specific quantum states. We describe a quantum algorithm for generating any prescribed quantum state. For an important subclass of states, including pure symmetric states, this algorithm is efficient.

  14. Quantum physics without quantum philosophy

    Energy Technology Data Exchange (ETDEWEB)

    Duerr, Detlef [Muenchen Univ. (Germany). Mathematisches Inst.; Goldstein, Sheldon [Rutgers State Univ., Piscataway, NJ (United States). Dept. of Mathematics; Zanghi, Nino [Genova Univ. (Italy); Istituto Nazionale Fisica Nucleare, Genova (Italy)

    2013-02-01

    Integrates and comments on the authors' seminal papers in the field. Emphasizes the natural way in which quantum phenomena emerge from the Bohmian picture. Helps to answer many of the objections raised to Bohmian quantum mechanics. Useful overview and summary for newcomers and students. It has often been claimed that without drastic conceptual innovations a genuine explanation of quantum interference effects and quantum randomness is impossible. This book concerns Bohmian mechanics, a simple particle theory that is a counterexample to such claims. The gentle introduction and other contributions collected here show how the phenomena of non-relativistic quantum mechanics, from Heisenberg's uncertainty principle to non-commuting observables, emerge from the Bohmian motion of particles, the natural particle motion associated with Schroedinger's equation. This book will be of value to all students and researchers in physics with an interest in the meaning of quantum theory as well as to philosophers of science.

  15. Quantum entanglement and quantum operation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It is a simple introduction to quantum entanglement and quantum operations.The authors focus on some applications of quantum entanglement and relations between two-qubit entangled states and unitary operations.It includes remote state preparation by using any pure entangled states,nonlocal operation implementation using entangled states,entanglement capacity of two-qubit gates and two-qubit gates construction.

  16. Quantum Physics Without Quantum Philosophy

    CERN Document Server

    Dürr, Detlef; Zanghì, Nino

    2013-01-01

    It has often been claimed that without drastic conceptual innovations a genuine explanation of quantum interference effects and quantum randomness is impossible. This book concerns Bohmian mechanics, a simple particle theory that is a counterexample to such claims. The gentle introduction and other contributions collected here show how the phenomena of non-relativistic quantum mechanics, from Heisenberg's uncertainty principle to non-commuting observables, emerge from the Bohmian motion of particles, the natural particle motion associated with Schrödinger's equation. This book will be of value to all students and researchers in physics with an interest in the meaning of quantum theory as well as to philosophers of science.

  17. Quantum Algorithms

    Science.gov (United States)

    Abrams, D.; Williams, C.

    1999-01-01

    This thesis describes several new quantum algorithms. These include a polynomial time algorithm that uses a quantum fast Fourier transform to find eigenvalues and eigenvectors of a Hamiltonian operator, and that can be applied in cases for which all know classical algorithms require exponential time.

  18. Quantum Theory

    CERN Document Server

    Manning, Phillip

    2011-01-01

    The study of quantum theory allowed twentieth-century scientists to examine the world in a new way, one that was filled with uncertainties and probabilities. Further study also led to the development of lasers, the atomic bomb, and the computer. This exciting new book clearly explains quantum theory and its everyday uses in our world.

  19. Quantum Gravitodynamics

    CERN Document Server

    Sastry, R R

    1999-01-01

    The infinite dimensional generalization of the quantum mechanics of extended objects, namely, the quantum field theory of extended objects is employed to address the hitherto nonrenormalizable gravitational interaction following which the cosmological constant problem is addressed. The response of an electron to a weak gravitational field (linear approximation) is studied and the order $\\alpha$ correction to the magnetic gravitational moment is computed.

  20. Quantum entanglement

    CERN Document Server

    Hadjiivanov, Ludmil

    2015-01-01

    Expository paper providing a historical survey of the gradual transformation of the "philosophical discussions" between Bohr, Einstein and Schr\\"odinger on foundational issues in quantum mechanics into a quantitative prediction of a new quantum effect, its experimental verification and its proposed (and loudly advertised) applications. The basic idea of the 1935 paper of Einstein-Podolsky-Rosen (EPR) was reformulated by David Bohm for a finite dimensional spin system. This allowed John Bell to derive his inequalities that separate the prediction of quantum entanglement from its possible classical interpretation. We reproduce here their later (1971) version, reviewing on the way the generalization (and mathematical derivation) of Heisenberg's uncertainty relations (due to Weyl and Schr\\"odinger) needed for the passage from EPR to Bell. We also provide an improved derivation of the quantum theoretic violation of Bell's inequalities. Soon after the experimental confirmation of the quantum entanglement (culminati...

  1. Quantum magnetism

    CERN Document Server

    Richter, Johannes; Farnell, Damian; Bishop, Raymod

    2004-01-01

    The investigation of magnetic systems where quantum effects play a dominant role has become a very active branch of solid-state-physics research in its own right. The first three chapters of the "Quantum Magnetism" survey conceptual problems and provide insights into the classes of systems considered, namely one-dimensional, two-dimensional and molecular magnets. The following chapters introduce the methods used in the field of quantum magnetism, including spin wave analysis, exact diagonalization, quantum field theory, coupled cluster methods and the Bethe ansatz. The book closes with a chapter on quantum phase transitions and a contribution that puts the wealth of phenomena into the context of experimental solid-state physics. Closing a gap in the literature, this volume is intended both as an introductory text at postgraduate level and as a modern, comprehensive reference for researchers in the field.

  2. Quantum photonics

    CERN Document Server

    Pearsall, Thomas P

    2017-01-01

    This textbook employs a pedagogical approach that facilitates access to the fundamentals of Quantum Photonics. It contains an introductory description of the quantum properties of photons through the second quantization of the electromagnetic field, introducing stimulated and spontaneous emission of photons at the quantum level. Schrödinger’s equation is used to describe the behavior of electrons in a one-dimensional potential. Tunneling through a barrier is used to introduce the concept of non­locality of an electron at the quantum level, which is closely-related to quantum confinement tunneling, resonant tunneling, and the origin of energy bands in both periodic (crystalline) and aperiodic (non-crystalline) materials. Introducing the concepts of reciprocal space, Brillouin zones, and Bloch’s theorem, the determination of electronic band structure using the pseudopotential method is presented, allowing direct computation of the band structures of most group IV, group III-V, and group II-VI semiconducto...

  3. Quantum gravity

    CERN Document Server

    Kiefer, Claus

    2012-01-01

    The search for a quantum theory of the gravitational field is one of the great open problems in theoretical physics. This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory. The two main approaches to its construction - the direct quantisation of Einstein's general theory of relativity and string theory - are covered. Whereas the first attempts to construct a viable theory for the gravitational field alone, string theory assumes that a quantum theory of gravity will be achieved only through a unification of all the interactions. However, both employ the general method of quantization of constrained systems, which is described together with illustrative examples relevant for quantum gravity. There is a detailed presentation of the main approaches employed in quantum general relativity: path-integral quantization, the background-field method and canonical quantum gravity in the metric, connection and loop formulations. The discussion of stri...

  4. Quantum mechanics

    CERN Document Server

    Rae, Alastair I M

    2016-01-01

    A Thorough Update of One of the Most Highly Regarded Textbooks on Quantum Mechanics Continuing to offer an exceptionally clear, up-to-date treatment of the subject, Quantum Mechanics, Sixth Edition explains the concepts of quantum mechanics for undergraduate students in physics and related disciplines and provides the foundation necessary for other specialized courses. This sixth edition builds on its highly praised predecessors to make the text even more accessible to a wider audience. It is now divided into five parts that separately cover broad topics suitable for any general course on quantum mechanics. New to the Sixth Edition * Three chapters that review prerequisite physics and mathematics, laying out the notation, formalism, and physical basis necessary for the rest of the book * Short descriptions of numerous applications relevant to the physics discussed, giving students a brief look at what quantum mechanics has made possible industrially and scientifically * Additional end-of-chapter problems with...

  5. Quantum Computation Toward Quantum Gravity

    Science.gov (United States)

    Zizzi, P. A.

    2001-08-01

    The aim of this paper is to enlighten the emerging relevance of Quantum Information Theory in the field of Quantum Gravity. As it was suggested by J. A. Wheeler, information theory must play a relevant role in understanding the foundations of Quantum Mechanics (the "It from bit" proposal). Here we suggest that quantum information must play a relevant role in Quantum Gravity (the "It from qubit" proposal). The conjecture is that Quantum Gravity, the theory which will reconcile Quantum Mechanics with General Relativity, can be formulated in terms of quantum bits of information (qubits) stored in space at the Planck scale. This conjecture is based on the following arguments: a) The holographic principle, b) The loop quantum gravity approach and spin networks, c) Quantum geometry and black hole entropy. From the above arguments, as they stand in the literature, it follows that the edges of spin networks pierce the black hole horizon and excite curvature degrees of freedom on the surface. These excitations are micro-states of Chern-Simons theory and account of the black hole entropy which turns out to be a quarter of the area of the horizon, (in units of Planck area), in accordance with the holographic principle. Moreover, the states which dominate the counting correspond to punctures of spin j = 1/2 and one can in fact visualize each micro-state as a bit of information. The obvious generalization of this result is to consider open spin networks with edges labeled by the spin -1/ 2 representation of SU(2) in a superposed state of spin "on" and spin "down." The micro-state corresponding to such a puncture will be a pixel of area which is "on" and "off" at the same time, and it will encode a qubit of information. This picture, when applied to quantum cosmology, describes an early inflationary universe which is a discrete version of the de Sitter universe.

  6. Quantum communications

    CERN Document Server

    Cariolaro, Gianfranco

    2015-01-01

    This book demonstrates that a quantum communication system using the coherent light of a laser can achieve performance orders of magnitude superior to classical optical communications Quantum Communications provides the Masters and PhD signals or communications student with a complete basics-to-applications course in using the principles of quantum mechanics to provide cutting-edge telecommunications. Assuming only knowledge of elementary probability, complex analysis and optics, the book guides its reader through the fundamentals of vector and Hilbert spaces and the necessary quantum-mechanical ideas, simply formulated in four postulates. A turn to practical matters begins with and is then developed by: ·         development of the concept of quantum decision, emphasizing the optimization of measurements to extract useful information from a quantum system; ·         general formulation of a transmitter–receiver system ·         particular treatment of the most popular quantum co...

  7. Quantum Computers and Quantum Computer Languages: Quantum Assembly Language and Quantum C Language

    OpenAIRE

    Blaha, Stephen

    2002-01-01

    We show a representation of Quantum Computers defines Quantum Turing Machines with associated Quantum Grammars. We then create examples of Quantum Grammars. Lastly we develop an algebraic approach to high level Quantum Languages using Quantum Assembly language and Quantum C language as examples.

  8. Quantum Computers and Quantum Computer Languages: Quantum Assembly Language and Quantum C

    OpenAIRE

    Blaha, Stephen

    2002-01-01

    We show a representation of Quantum Computers defines Quantum Turing Machines with associated Quantum Grammars. We then create examples of Quantum Grammars. Lastly we develop an algebraic approach to high level Quantum Languages using Quantum Assembly language and Quantum C language as examples.

  9. Quantum Computers and Quantum Computer Languages: Quantum Assembly Language and Quantum C

    OpenAIRE

    Blaha, Stephen

    2002-01-01

    We show a representation of Quantum Computers defines Quantum Turing Machines with associated Quantum Grammars. We then create examples of Quantum Grammars. Lastly we develop an algebraic approach to high level Quantum Languages using Quantum Assembly language and Quantum C language as examples.

  10. Quantum Computers and Quantum Computer Languages: Quantum Assembly Language and Quantum C Language

    OpenAIRE

    Blaha, Stephen

    2002-01-01

    We show a representation of Quantum Computers defines Quantum Turing Machines with associated Quantum Grammars. We then create examples of Quantum Grammars. Lastly we develop an algebraic approach to high level Quantum Languages using Quantum Assembly language and Quantum C language as examples.

  11. Cascade quantum teleportation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Nan-run; GONG Li-hua; LIU Ye

    2006-01-01

    In this letter a cascade quantum teleportation scheme is proposed. The proposed scheme needs less local quantum operations than those of quantum multi-teleportation. A quantum teleportation scheme based on entanglement swapping is presented and compared with the cascade quantum teleportation scheme. Those two schemes can effectively teleport quantum information and extend the distance of quantum communication.

  12. Quantum probability

    CERN Document Server

    Gudder, Stanley P

    2014-01-01

    Quantum probability is a subtle blend of quantum mechanics and classical probability theory. Its important ideas can be traced to the pioneering work of Richard Feynman in his path integral formalism.Only recently have the concept and ideas of quantum probability been presented in a rigorous axiomatic framework, and this book provides a coherent and comprehensive exposition of this approach. It gives a unified treatment of operational statistics, generalized measure theory and the path integral formalism that can only be found in scattered research articles.The first two chapters survey the ne

  13. Quantum mechanics

    CERN Document Server

    Powell, John L

    2015-01-01

    Suitable for advanced undergraduates, this thorough text focuses on the role of symmetry operations and the essentially algebraic structure of quantum-mechanical theory. Based on courses in quantum mechanics taught by the authors, the treatment provides numerous problems that require applications of theory and serve to supplement the textual material.Starting with a historical introduction to the origins of quantum theory, the book advances to discussions of the foundations of wave mechanics, wave packets and the uncertainty principle, and an examination of the Schrödinger equation that includ

  14. Quantum Optics

    CERN Document Server

    Garrison, J C

    2008-01-01

    Quantum optics, i.e. the interaction of individual photons with matter, began with the discoveries of Planck and Einstein, but in recent years it has expanded beyond pure physics to become an important driving force for technological innovation. This book serves the broader readership growing out of this development by starting with an elementary description of the underlying physics and then building up a more advanced treatment. The reader is led from the quantum theory of thesimple harmonic oscillator to the application of entangled states to quantum information processing. An equally impor

  15. Quantum chemistry

    CERN Document Server

    Lowe, John P

    1993-01-01

    Praised for its appealing writing style and clear pedagogy, Lowe's Quantum Chemistry is now available in its Second Edition as a text for senior undergraduate- and graduate-level chemistry students. The book assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry, thus enabling students to comprehend much of the current chemical literature in which quantum chemical methods or concepts are used as tools. The book begins with a six-chapter introduction of standard one-dimensional systems, the hydrogen atom,

  16. Quantum algorithmic information theory

    OpenAIRE

    Svozil, Karl

    1995-01-01

    The agenda of quantum algorithmic information theory, ordered `top-down,' is the quantum halting amplitude, followed by the quantum algorithmic information content, which in turn requires the theory of quantum computation. The fundamental atoms processed by quantum computation are the quantum bits which are dealt with in quantum information theory. The theory of quantum computation will be based upon a model of universal quantum computer whose elementary unit is a two-port interferometer capa...

  17. Quantum fingerprinting

    CERN Document Server

    Buhrman, H; Watrous, J; De Wolf, R; Buhrman, Harry; Cleve, Richard; Watrous, John; Wolf, Ronald de

    2001-01-01

    Classical fingerprinting associates with each string a shorter string (its fingerprint), such that, with high probability, any two distinct strings can be distinguished by comparing their fingerprints alone. The fingerprints can be exponentially smaller than the original strings if the parties preparing the fingerprints share a random key, but not if they only have access to uncorrelated random sources. In this paper we show that fingerprints consisting of quantum information can be made exponentially smaller than the original strings without any correlations or entanglement between the parties: we give a scheme where the quantum fingerprints are exponentially shorter than the original strings and we give a test that distinguishes any two unknown quantum fingerprints with high probability. Our scheme implies an exponential quantum/classical gap for the equality problem in the simultaneous message passing model of communication complexity. We optimize several aspects of our scheme.

  18. Quantum computers.

    Science.gov (United States)

    Ladd, T D; Jelezko, F; Laflamme, R; Nakamura, Y; Monroe, C; O'Brien, J L

    2010-03-04

    Over the past several decades, quantum information science has emerged to seek answers to the question: can we gain some advantage by storing, transmitting and processing information encoded in systems that exhibit unique quantum properties? Today it is understood that the answer is yes, and many research groups around the world are working towards the highly ambitious technological goal of building a quantum computer, which would dramatically improve computational power for particular tasks. A number of physical systems, spanning much of modern physics, are being developed for quantum computation. However, it remains unclear which technology, if any, will ultimately prove successful. Here we describe the latest developments for each of the leading approaches and explain the major challenges for the future.

  19. Quantum Rotatability

    CERN Document Server

    Curran, Stephen

    2009-01-01

    In arXiv:0807.0677, K\\"ostler and Speicher observed that de Finetti's theorem on exchangeable sequences has a free analogue if one replaces exchangeability by the stronger condition of invariance under quantum permutations. In this paper we study sequences of noncommutative random variables whose joint distribution is invariant under quantum orthogonal transformations. We prove a free analogue of Freedman's characterization of conditionally independent Gaussian families, namely an infinite sequence of self-adjoint random variables is quantum orthogonally invariant if and only if they form an operator-valued free centered equivariant semicircular family. Similarly, we show that an infinite sequence of noncommutative random variables is quantum unitarily invariant if and only if they form an operator-valued free centered equivariant circular family. We provide an example to show that, as in the classical case, these results fail for finite sequences. We then give an approximation to how far the distribution of ...

  20. Quantum Brain?

    CERN Document Server

    Mershin, A; Skoulakis, E M C

    2000-01-01

    In order to create a novel model of memory and brain function, we focus our approach on the sub-molecular (electron), molecular (tubulin) and macromolecular (microtubule) components of the neural cytoskeleton. Due to their size and geometry, these systems may be approached using the principles of quantum physics. We identify quantum-physics derived mechanisms conceivably underlying the integrated yet differentiated aspects of memory encoding/recall as well as the molecular basis of the engram. We treat the tubulin molecule as the fundamental computation unit (qubit) in a quantum-computational network that consists of microtubules (MTs), networks of MTs and ultimately entire neurons and neural networks. We derive experimentally testable predictions of our quantum brain hypothesis and perform experiments on these.

  1. Quantum lottery

    CERN Document Server

    CERN Bulletin

    2013-01-01

    On April Fools' Day, CERN Quantum Diaries blogger Pauline Gagnon held a giveaway of microscopic proportion. Up for grabs? Ten Higgs bosons, courtesy of CERN. Pauline announced the winners last week; let's see what they'll really be getting in the mail...   Custom-made Particle Zoo Higgs bosons were sent out to the winners. Read more about the prize in the Quantum Diaries post "Higgs boson lottery: when CERN plays April Fools' jokes".

  2. Quantum Physics

    OpenAIRE

    Haroche, Serge

    2013-01-01

    Mr Administrator,Dear colleagues,Ladies and gentlemen, “I think I can safely say that nobody understands quantum mechanics”. This statement, made by physicist Richard Feynman, expresses a paradoxical truth about the scientific theory that revolutionised our understanding of Nature and made an extraordinary contribution to our means of acting on and gaining information about the world. In this lecture, I will discuss quantum physics with you by attempting to resolve this paradox. And if I don’...

  3. Quantum optics

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund

    2013-01-01

    Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves.......Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves....

  4. Quantum Plasmonics

    OpenAIRE

    Diego Martin-Cano, Paloma A. Huidobro, Esteban Moreno; Diego Martin-Cano; Huidobro, Paloma A.; Esteban Moreno; Garcia-Vidal, F.J.

    2014-01-01

    Quantum plasmonics is a rapidly growing field of research that involves the study of the quantum properties of light and its interaction with matter at the nanoscale. Here, surface plasmons - electromagnetic excitations coupled to electron charge density waves on metal-dielectric interfaces or localized on metallic nanostructures - enable the confinement of light to scales far below that of conventional optics. In this article we review recent progress in the experimental and theoretical inve...

  5. Quantum optics

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund

    2013-01-01

    Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves.......Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves....

  6. Quantum correlations and distinguishability of quantum states

    Science.gov (United States)

    Spehner, Dominique

    2014-07-01

    A survey of various concepts in quantum information is given, with a main emphasis on the distinguishability of quantum states and quantum correlations. Covered topics include generalized and least square measurements, state discrimination, quantum relative entropies, the Bures distance on the set of quantum states, the quantum Fisher information, the quantum Chernoff bound, bipartite entanglement, the quantum discord, and geometrical measures of quantum correlations. The article is intended both for physicists interested not only by collections of results but also by the mathematical methods justifying them, and for mathematicians looking for an up-to-date introductory course on these subjects, which are mainly developed in the physics literature.

  7. Delirium Quantum

    CERN Document Server

    Fuchs, Christopher A

    2009-01-01

    This pseudo-paper consists of excerpts drawn from two of my quantum-email samizdats. Section 1 draws a picture of a physical world whose essence is ``Darwinism all the way down.'' Section 2 outlines how quantum theory should be viewed in light of this, i.e., as being an expression of probabilism (in Bruno de Finetti or Richard Jeffrey's sense) all the way back up. Section 3 describes how the idea of ``identical'' quantum measurement outcomes, though sounding atomistic in character, nonetheless meshes well with a Jamesian style ``radical pluralism.'' Sections 4 and 5 further detail how quantum theory should not be viewed so much as a ``theory of the world,'' but rather as a theory of decision-making for agents immersed within a world of a particular character--the quantum world. Finally, Sections 6 and 7 attempt to sketch the very positive sense in which quantum theory is incomplete, but still just as complete is it can be. In total, I hope these heady speculations convey some of the excitement and potential I...

  8. Quantum Computation and Quantum Spin Dynamics

    NARCIS (Netherlands)

    Raedt, Hans De; Michielsen, Kristel; Hams, Anthony; Miyashita, Seiji; Saito, Keiji

    2001-01-01

    We analyze the stability of quantum computations on physically realizable quantum computers by simulating quantum spin models representing quantum computer hardware. Examples of logically identical implementations of the controlled-NOT operation are used to demonstrate that the results of a quantum

  9. Quantum Central Processing Unit and Quantum Algorithm

    Institute of Scientific and Technical Information of China (English)

    王安民

    2002-01-01

    Based on a scalable and universal quantum network, quantum central processing unit, proposed in our previous paper [Chin. Phys. Left. 18 (2001)166], the whole quantum network for the known quantum algorithms,including quantum Fourier transformation, Shor's algorithm and Grover's algorithm, is obtained in a unitied way.

  10. Quantum Computation and Quantum Spin Dynamics

    NARCIS (Netherlands)

    Raedt, Hans De; Michielsen, Kristel; Hams, Anthony; Miyashita, Seiji; Saito, Keiji

    2001-01-01

    We analyze the stability of quantum computations on physically realizable quantum computers by simulating quantum spin models representing quantum computer hardware. Examples of logically identical implementations of the controlled-NOT operation are used to demonstrate that the results of a quantum

  11. Quantum Physics for Beginners.

    Science.gov (United States)

    Strand, J.

    1981-01-01

    Suggests a new approach for teaching secondary school quantum physics. Reviews traditional approaches and presents some characteristics of the three-part "Quantum Physics for Beginners" project, including: quantum physics, quantum mechanics, and a short historical survey. (SK)

  12. Quantum Transmemetic Intelligence

    Science.gov (United States)

    Piotrowski, Edward W.; Sładkowski, Jan

    The following sections are included: * Introduction * A Quantum Model of Free Will * Quantum Acquisition of Knowledge * Thinking as a Quantum Algorithm * Counterfactual Measurement as a Model of Intuition * Quantum Modification of Freud's Model of Consciousness * Conclusion * Acknowledgements * References

  13. Quantum Physics for Beginners.

    Science.gov (United States)

    Strand, J.

    1981-01-01

    Suggests a new approach for teaching secondary school quantum physics. Reviews traditional approaches and presents some characteristics of the three-part "Quantum Physics for Beginners" project, including: quantum physics, quantum mechanics, and a short historical survey. (SK)

  14. Quantum Mechanics

    Science.gov (United States)

    Mandl, F.

    1992-07-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A. C. Phillips Computing for Scientists R. J. Barlow and A. R. Barnett Quantum Mechanics aims to teach those parts of the subject which every physicist should know. The object is to display the inherent structure of quantum mechanics, concentrating on general principles and on methods of wide applicability without taking them to their full generality. This book will equip students to follow quantum-mechanical arguments in books and scientific papers, and to cope with simple cases. To bring the subject to life, the theory is applied to the all-important field of atomic physics. No prior knowledge of quantum mechanics is assumed. However, it would help most readers to have met some elementary wave mechanics before. Primarily written for students, it should also be of interest to experimental research workers who require a good grasp of quantum mechanics without the full formalism needed by the professional theorist. Quantum Mechanics features: A flow diagram allowing topics to be studied in different orders or omitted altogether. Optional "starred" and highlighted sections containing more advanced and specialized material for the more ambitious reader. Sets of problems at the end of each chapter to help student understanding. Hints and solutions to the problems are given at the end of the book.

  15. Quantum weirdness

    CERN Document Server

    Mullin, William J

    2017-01-01

    Quantum mechanics allows a remarkably accurate description of nature and powerful predictive capabilities. The analyses of quantum systems and their interpretation lead to many surprises, for example, the ability to detect the characteristics of an object without ever touching it in any way, via "interaction-free measurement," or the teleportation of an atomic state over large distances. The results can become downright bizarre. Quantum mechanics is a subtle subject that usually involves complicated mathematics -- calculus, partial differential equations, etc., for complete understanding. Most texts for general audiences avoid all mathematics. The result is that the reader misses almost all deep understanding of the subject, much of which can be probed with just high-school level algebra and trigonometry. Thus, readers with that level of mathematics can learn so much more about this fundamental science. The book starts with a discussion of the basic physics of waves (an appendix reviews some necessary class...

  16. Quantum mechanics

    CERN Document Server

    Fitzpatrick, Richard

    2015-01-01

    Quantum mechanics was developed during the first few decades of the twentieth century via a series of inspired guesses made by various physicists, including Planck, Einstein, Bohr, Schroedinger, Heisenberg, Pauli, and Dirac. All these scientists were trying to construct a self-consistent theory of microscopic dynamics that was compatible with experimental observations. The purpose of this book is to present quantum mechanics in a clear, concise, and systematic fashion, starting from the fundamental postulates, and developing the theory in as logical manner as possible. Topics covered in the book include the fundamental postulates of quantum mechanics, angular momentum, time-dependent and time-dependent perturbation theory, scattering theory, identical particles, and relativistic electron theory.

  17. Quantum spirals

    CERN Document Server

    Yoshida, Z

    2016-01-01

    Quantum systems often exhibit fundamental incapability to entertain vortex. The Meissner effect, a complete expulsion of the magnetic field (the electromagnetic vorticity), for instance, is taken to be the defining attribute of the superconducting state. Superfluidity is another, close-parallel example; fluid vorticity can reside only on topological defects with a limited (quantized) amount. Recent developments in the Bose-Einstein condensates produced by particle traps further emphasize this characteristic. We show that the challenge of imparting vorticity to a quantum fluid can be met through a nonlinear mechanism operating in a hot fluid corresponding to a thermally modified Pauli-Schroedinger spinor field. In a simple field-free model, we show that the thermal effect, represented by a nonlinear, non-Hermitian Hamiltonian, in conjunction with spin vorticity, leads to new interesting quantum states; a spiral solution is explicitly worked out.

  18. Quantum waveguides

    CERN Document Server

    Exner, Pavel

    2015-01-01

    This monograph explains the theory of quantum waveguides, that is, dynamics of quantum particles confined to regions in the form of tubes, layers, networks, etc. The focus is on relations between the confinement geometry on the one hand and the spectral and scattering properties of the corresponding quantum Hamiltonians on the other. Perturbations of such operators, in particular, by external fields are also considered. The volume provides a unique summary of twenty five years of research activity in this area and indicates ways in which the theory can develop further. The book is fairly self-contained. While it requires some broader mathematical physics background, all the basic concepts are properly explained and proofs of most theorems are given in detail, so there is no need for additional sources. Without a parallel in the literature, the monograph by Exner and Kovarik guides the reader through this new and exciting field.

  19. Quantum Spring

    Science.gov (United States)

    Feng, Chao-Jun; Li, Xin-Zhou

    In this paper, we will give a short review on quantum spring, which is a Casimir effect from the helix boundary condition that proposed in our earlier works. The Casimir force parallel to the axis of the helix behaves very much like the force on a spring that obeys the Hooke's law when the ratio r of the pitch to the circumference of the helix is small, but in this case, the force comes from a quantum effect, so we would like to call it quantum spring. On the other hand, the force perpendicular to the axis decreases monotonously with the increasing of the ratio r. Both forces are attractive and their behaviors are the same in two and three dimensions.

  20. Quantum Go

    CERN Document Server

    Ranchin, André

    2016-01-01

    We introduce a new board game based on the ancient Chinese game of Go (Weiqi, Igo, Baduk). The key difference from the original game is that players no longer alternatively play single stones on the board but instead they take turns placing pairs of entangled go stones. A phenomenon of quantum-like collapse occurs when a stone is placed in an intersection directly adjacent to one or more other stones. For each neighboring stone in an entangled pair, each player then chooses which stone of the pair is kept on the board and which stone is removed. The aim of the game is still to surround more territory than the opponent and as the number of stones increases, all the entangled pairs of stones eventually reduce to single stones. Quantum Go provides an interesting and tangible illustration of quantum concepts such as superposition, entanglement and collapse.

  1. Quantum Magnetism

    CERN Document Server

    Barbara, Bernard; Sawatzky, G; Stamp, P. C. E

    2008-01-01

    This book is based on some of the lectures during the Pacific Institute of Theoretical Physics (PITP) summer school on "Quantum Magnetism", held during June 2006 in Les Houches, in the French Alps. The school was funded jointly by NATO, the CNRS, and PITP, and entirely organized by PITP. Magnetism is a somewhat peculiar research field. It clearly has a quantum-mechanical basis – the microsopic exchange interactions arise entirely from the exclusion principle, in conjunction with respulsive interactions between electrons. And yet until recently the vast majority of magnetism researchers and users of magnetic phenomena around the world paid no attention to these quantum-mechanical roots. Thus, eg., the huge ($400 billion per annum) industry which manufactures hard discs, and other components in the information technology sector, depends entirely on room-temperature properties of magnets - yet at the macroscopic or mesoscopic scales of interest to this industry, room-temperature magnets behave entirely classic...

  2. Quantum mechanics

    CERN Document Server

    Ghosh, P K

    2014-01-01

    Quantum mechanics, designed for advanced undergraduate and graduate students of physics, mathematics and chemistry, provides a concise yet self-contained introduction to the formal framework of quantum mechanics, its application to physical problems and the interpretation of the theory. Starting with a review of some of the necessary mathematics, the basic concepts are carefully developed in the text. After building a general formalism, detailed treatment of the standard material - the harmonic oscillator, the hydrogen atom, angular momentum theory, symmetry transformations, approximation methods, identical particle and many-particle systems, and scattering theory - is presented. The concluding chapter discusses the interpretation of quantum mechanics. Some of the important topics discussed in the book are the rigged Hilbert space, deformation quantization, path integrals, coherent states, geometric phases, decoherene, etc. This book is characterized by clarity and coherence of presentation.

  3. Quantum mechanics

    CERN Document Server

    Rae, Alastair I M

    2007-01-01

    PREFACESINTRODUCTION The Photoelectric Effect The Compton Effect Line Spectra and Atomic Structure De Broglie Waves Wave-Particle Duality The Rest of This Book THE ONE-DIMENSIONAL SCHRÖDINGER EQUATIONS The Time-Dependent Schrödinger Equation The Time-Independent Schrödinger Equation Boundary ConditionsThe Infinite Square Well The Finite Square Well Quantum Mechanical Tunneling The Harmonic Oscillator THE THREE-DIMENSIONAL SCHRÖDINGER EQUATIONS The Wave Equations Separation in Cartesian Coordinates Separation in Spherical Polar Coordinates The Hydrogenic Atom THE BASIC POSTULATES OF QUANTUM MEC

  4. Quantum mechanics

    CERN Document Server

    Zagoskin, Alexandre

    2015-01-01

    Written by Dr Alexandre Zagoskin, who is a Reader at Loughborough University, Quantum Mechanics: A Complete Introduction is designed to give you everything you need to succeed, all in one place. It covers the key areas that students are expected to be confident in, outlining the basics in clear jargon-free English, and then providing added-value features like summaries of key ideas, and even lists of questions you might be asked in your exam. The book uses a structure that is designed to make quantum physics as accessible as possible - by starting with its similarities to Newtonian physics, ra

  5. Quantum dice

    OpenAIRE

    de Bianchi, Massimiliano Sassoli

    2013-01-01

    In a letter to Born, Einstein wrote: "Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the old one. I, at any rate, am convinced that He does not throw dice." In this paper we take seriously Einstein's famous metaphor, and show that we can gain considerable insight into quantum mechanics by doing something as simple as rolling dice. More precisely, we show how...

  6. Quantum Cosmology

    OpenAIRE

    Bojowald, Martin

    1999-01-01

    A complete model of the universe needs at least three parts: (1) a complete set of physical variables and dynamical laws for them, (2) the correct solution of the dynamical laws, and (3) the connection with conscious experience. In quantum cosmology, item (2) is the quantum state of the cosmos. Hartle and Hawking have made the `no-boundary' proposal, that the wavefunction of the universe is given by a path integral over all compact Euclidean 4-dimensional geometries and matter fields that hav...

  7. Quantum protocols

    OpenAIRE

    Buhrman, Harry

    2006-01-01

    École thématique; Quantum Information, Computation and Complexity * Programme at the Institut Henri Poincaré, January 4th – April 7th, 2006 * Organizers: Ph.Grangier, M.Santha and D.L.Shepelyansky * Lectures have been filmed by Peter Rapcan and Michal Sedlak from Bratislava with the support of the Marie Curie RTN "CONQUEST" A trimester at the Centre Emile Borel - Institut Henri Poincaré is devoted to modern developments in a rapidly growing field of quantum information and communication, quan...

  8. Quantum Finance

    Science.gov (United States)

    Baaquie, Belal E.

    2007-09-01

    Foreword; Preface; Acknowledgements; 1. Synopsis; Part I. Fundamental Concepts of Finance: 2. Introduction to finance; 3. Derivative securities; Part II. Systems with Finite Number of Degrees of Freedom: 4. Hamiltonians and stock options; 5. Path integrals and stock options; 6. Stochastic interest rates' Hamiltonians and path integrals; Part III. Quantum Field Theory of Interest Rates Models: 7. Quantum field theory of forward interest rates; 8. Empirical forward interest rates and field theory models; 9. Field theory of Treasury Bonds' derivatives and hedging; 10. Field theory Hamiltonian of forward interest rates; 11. Conclusions; Appendix A: mathematical background; Brief glossary of financial terms; Brief glossary of physics terms; List of main symbols; References; Index.

  9. Quantum profiles

    CERN Document Server

    Bernstein, Jeremy

    1991-01-01

    For the prominent science writer Jeremy Bernstein, the profile is the most congenial way of communicating science. Here, in what he labels a "series of conversations carried on in the reader's behalf and my own," he evokes the tremendous intellectual excitement of the world of modern physics, especially the quantum revolution. Drawing on his well-known talent for explaining the most complex scientific ideas for the layperson, Bernstein gives us a lively sense of what the issues of quantum mechanics are and of various ways in which individual physicists approached them.The author begins this se

  10. Blind Quantum Signature with Blind Quantum Computation

    Science.gov (United States)

    Li, Wei; Shi, Ronghua; Guo, Ying

    2017-04-01

    Blind quantum computation allows a client without quantum abilities to interact with a quantum server to perform a unconditional secure computing protocol, while protecting client's privacy. Motivated by confidentiality of blind quantum computation, a blind quantum signature scheme is designed with laconic structure. Different from the traditional signature schemes, the signing and verifying operations are performed through measurement-based quantum computation. Inputs of blind quantum computation are securely controlled with multi-qubit entangled states. The unique signature of the transmitted message is generated by the signer without leaking information in imperfect channels. Whereas, the receiver can verify the validity of the signature using the quantum matching algorithm. The security is guaranteed by entanglement of quantum system for blind quantum computation. It provides a potential practical application for e-commerce in the cloud computing and first-generation quantum computation.

  11. Blind Quantum Signature with Blind Quantum Computation

    Science.gov (United States)

    Li, Wei; Shi, Ronghua; Guo, Ying

    2016-12-01

    Blind quantum computation allows a client without quantum abilities to interact with a quantum server to perform a unconditional secure computing protocol, while protecting client's privacy. Motivated by confidentiality of blind quantum computation, a blind quantum signature scheme is designed with laconic structure. Different from the traditional signature schemes, the signing and verifying operations are performed through measurement-based quantum computation. Inputs of blind quantum computation are securely controlled with multi-qubit entangled states. The unique signature of the transmitted message is generated by the signer without leaking information in imperfect channels. Whereas, the receiver can verify the validity of the signature using the quantum matching algorithm. The security is guaranteed by entanglement of quantum system for blind quantum computation. It provides a potential practical application for e-commerce in the cloud computing and first-generation quantum computation.

  12. Quantum Time

    CERN Document Server

    Ashmead, John

    2010-01-01

    Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do this, we generalize the paths in the Feynman path integral to include paths that vary in time as well as in space. We use Morlet wavelet decomposition to ensure convergence and normalization of the path integrals. We derive the Schr\\"odinger equation in four dimensions from the short time limit of the path integral expression. We verify that we recover standard quantum theory in the non-relativistic, semi-classical, and long time limits. Quantum time is an experiment factory: most foundational experiments in quantum mechanics can be modified in a way that makes them tests of quantum time. We look at single and double slits in time, scattering by time-varying electric and magnetic fields, and the Aharonov-Bohm effect in time.

  13. Quantum Transport

    Science.gov (United States)

    1993-05-14

    Barbara , California, March 1993. I Carrier Dynamics in Quantum Wires Investigators: Wolfgang Porod I I Using the Monte Carlo technique, we have...8217.ubtle correlations between impunty scanenng events tin the "res;ence oft a ma.’neuc fle!dlp which are beyond Fermi’s Golden Rule. In this caper . we

  14. Quantum Theory

    NARCIS (Netherlands)

    Raedt, Hans De; Binder, K; Ciccotti, G

    1996-01-01

    The purpose of this set of lectures is to introduce the general concepts that are at the basis of the computer simulation algorithms that are used to study the behavior of condensed matter quantum systems. The emphasis is on the underlying concepts rather than on specific applications. Topics treate

  15. Quantum rendering

    Science.gov (United States)

    Lanzagorta, Marco O.; Gomez, Richard B.; Uhlmann, Jeffrey K.

    2003-08-01

    In recent years, computer graphics has emerged as a critical component of the scientific and engineering process, and it is recognized as an important computer science research area. Computer graphics are extensively used for a variety of aerospace and defense training systems and by Hollywood's special effects companies. All these applications require the computer graphics systems to produce high quality renderings of extremely large data sets in short periods of time. Much research has been done in "classical computing" toward the development of efficient methods and techniques to reduce the rendering time required for large datasets. Quantum Computing's unique algorithmic features offer the possibility of speeding up some of the known rendering algorithms currently used in computer graphics. In this paper we discuss possible implementations of quantum rendering algorithms. In particular, we concentrate on the implementation of Grover's quantum search algorithm for Z-buffering, ray-tracing, radiosity, and scene management techniques. We also compare the theoretical performance between the classical and quantum versions of the algorithms.

  16. Quantum dice

    Energy Technology Data Exchange (ETDEWEB)

    Sassoli de Bianchi, Massimiliano, E-mail: autoricerca@gmail.com

    2013-09-15

    In a letter to Born, Einstein wrote [42]: “Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the ‘old one.’ I, at any rate, am convinced that He does not throw dice.” In this paper we take seriously Einstein’s famous metaphor, and show that we can gain considerable insight into quantum mechanics by doing something as simple as rolling dice. More precisely, we show how to perform measurements on a single die, to create typical quantum interference effects, and how to connect (entangle) two identical dice, to maximally violate Bell’s inequality. -- Highlights: •Rolling a die is a quantum process admitting a Hilbert space representation. •Rolling experiments with a single die can produce interference effects. •Two connected dice can violate Bell’s inequality. •Correlations need to be created by the measurement, to violate Bell’s inequality.

  17. Quantum abacus

    Science.gov (United States)

    Cheon, Taksu; Tsutsui, Izumi; Fülöp, Tamás

    2004-09-01

    We show that the point interactions on a line can be utilized to provide U(2) family of qubit operations for quantum information processing. Qubits are realized as states localized in either side of the point interaction which represents a controllable gate. The qubit manipulation proceeds in a manner analogous to the operation of an abacus.

  18. Quantum Criticality

    OpenAIRE

    Keimer, Bernhard; Sachdev, Subir

    2011-01-01

    This is a review of the basic theoretical ideas of quantum criticality, and of their connection to numerous experiments on correlated electron compounds. A shortened, modified, and edited version appeared in Physics Today. This arxiv version has additional citations to the literature.

  19. Quantum fragmentation

    CERN Document Server

    Peschanski, R

    1993-01-01

    Phenomenological and theoretical aspects of fragmentation for elementary particles (resp. nuclei) are discussed. It is shown that some concepts of classical fragmentation remain relevant in a microscopic framework, exhibiting non-trivial properties of quantum relativistic field theory (resp. lattice percolation). Email contact: pesch@amoco.saclay.cea.fr

  20. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  1. Quantum biological information theory

    CERN Document Server

    Djordjevic, Ivan B

    2016-01-01

    This book is a self-contained, tutorial-based introduction to quantum information theory and quantum biology. It serves as a single-source reference to the topic for researchers in bioengineering, communications engineering, electrical engineering, applied mathematics, biology, computer science, and physics. The book provides all the essential principles of the quantum biological information theory required to describe the quantum information transfer from DNA to proteins, the sources of genetic noise and genetic errors as well as their effects. Integrates quantum information and quantum biology concepts; Assumes only knowledge of basic concepts of vector algebra at undergraduate level; Provides a thorough introduction to basic concepts of quantum information processing, quantum information theory, and quantum biology; Includes in-depth discussion of the quantum biological channel modelling, quantum biological channel capacity calculation, quantum models of aging, quantum models of evolution, quantum models o...

  2. Quantum cryptography beyond quantum key distribution

    NARCIS (Netherlands)

    A. Broadbent (Anne); C. Schaffner (Christian)

    2016-01-01

    textabstractQuantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness

  3. Quantum cryptography beyond quantum key distribution

    NARCIS (Netherlands)

    Broadbent, A.; Schaffner, C.

    2016-01-01

    Quantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness generation,

  4. Quantum cryptography beyond quantum key distribution

    NARCIS (Netherlands)

    Broadbent, A.; Schaffner, C.

    2016-01-01

    Quantum cryptography is the art and science of exploiting quantum mechanical effects in order to perform cryptographic tasks. While the most well-known example of this discipline is quantum key distribution (QKD), there exist many other applications such as quantum money, randomness generation, secu

  5. Efficient quantum walk on a quantum processor

    Science.gov (United States)

    Qiang, Xiaogang; Loke, Thomas; Montanaro, Ashley; Aungskunsiri, Kanin; Zhou, Xiaoqi; O'Brien, Jeremy L.; Wang, Jingbo B.; Matthews, Jonathan C. F.

    2016-05-01

    The random walk formalism is used across a wide range of applications, from modelling share prices to predicting population genetics. Likewise, quantum walks have shown much potential as a framework for developing new quantum algorithms. Here we present explicit efficient quantum circuits for implementing continuous-time quantum walks on the circulant class of graphs. These circuits allow us to sample from the output probability distributions of quantum walks on circulant graphs efficiently. We also show that solving the same sampling problem for arbitrary circulant quantum circuits is intractable for a classical computer, assuming conjectures from computational complexity theory. This is a new link between continuous-time quantum walks and computational complexity theory and it indicates a family of tasks that could ultimately demonstrate quantum supremacy over classical computers. As a proof of principle, we experimentally implement the proposed quantum circuit on an example circulant graph using a two-qubit photonics quantum processor.

  6. Quantum Secure Dialogue with Quantum Encryption

    Science.gov (United States)

    Ye, Tian-Yu

    2014-09-01

    How to solve the information leakage problem has become the research focus of quantum dialogue. In this paper, in order to overcome the information leakage problem in quantum dialogue, a novel approach for sharing the initial quantum state privately between communicators, i.e., quantum encryption sharing, is proposed by utilizing the idea of quantum encryption. The proposed protocol uses EPR pairs as the private quantum key to encrypt and decrypt the traveling photons, which can be repeatedly used after rotation. Due to quantum encryption sharing, the public announcement on the state of the initial quantum state is omitted, thus the information leakage problem is overcome. The information-theoretical efficiency of the proposed protocol is nearly 100%, much higher than previous information leakage resistant quantum dialogue protocols. Moreover, the proposed protocol only needs single-photon measurements and nearly uses single photons as quantum resource so that it is convenient to implement in practice.

  7. Efficient quantum walk on a quantum processor.

    Science.gov (United States)

    Qiang, Xiaogang; Loke, Thomas; Montanaro, Ashley; Aungskunsiri, Kanin; Zhou, Xiaoqi; O'Brien, Jeremy L; Wang, Jingbo B; Matthews, Jonathan C F

    2016-05-05

    The random walk formalism is used across a wide range of applications, from modelling share prices to predicting population genetics. Likewise, quantum walks have shown much potential as a framework for developing new quantum algorithms. Here we present explicit efficient quantum circuits for implementing continuous-time quantum walks on the circulant class of graphs. These circuits allow us to sample from the output probability distributions of quantum walks on circulant graphs efficiently. We also show that solving the same sampling problem for arbitrary circulant quantum circuits is intractable for a classical computer, assuming conjectures from computational complexity theory. This is a new link between continuous-time quantum walks and computational complexity theory and it indicates a family of tasks that could ultimately demonstrate quantum supremacy over classical computers. As a proof of principle, we experimentally implement the proposed quantum circuit on an example circulant graph using a two-qubit photonics quantum processor.

  8. Efficient quantum walk on a quantum processor

    OpenAIRE

    Qiang, Xiaogang; Loke, Thomas; Montanaro, Ashley; Aungskunsiri, Kanin; Zhou, Xiao-Qi; O'Brien, Jeremy; Wang, Jingbo; Matthews, Jonathan

    2016-01-01

    The random walk formalism is used across a wide range of applications, from modelling share prices to predicting population genetics. Likewise quantum walks have shown much potential as a frame- work for developing new quantum algorithms. In this paper, we present explicit efficient quantum circuits for implementing continuous-time quantum walks on the circulant class of graphs. These circuits allow us to sample from the output probability distributions of quantum walks on circulant graphs ef...

  9. Interpreting Quantum Discord in Quantum Metrology

    OpenAIRE

    Girolami, Davide

    2015-01-01

    Multipartite quantum systems show properties which do not admit a classical explanation. In particular, even nonentangled states can enjoy a kind of quantum correlations called quantum discord. I discuss some recent results on the role of quantum discord in metrology. Given an interferometric phase estimation protocol where the Hamiltonian is initially unknown to the experimentalist, the quantum discord of the probe state quantifies the minimum precision of the estimation. This provides a phy...

  10. Quantum Mechanics interpreted in Quantum Real Numbers

    CERN Document Server

    Corbett, J V; Corbett, John V; Durt, Thomas

    2002-01-01

    The concept of number is fundamental to the formulation of any physical theory. We give a heuristic motivation for the reformulation of Quantum Mechanics in terms of non-standard real numbers called Quantum Real Numbers. The standard axioms of quantum mechanics are re-interpreted. Our aim is to show that, when formulated in the language of quantum real numbers, the laws of quantum mechanics appear more natural, less counterintuitive than when they are presented in terms of standard numbers.

  11. Quantum Cosmology

    Science.gov (United States)

    Bojowald, Martin

    The universe, ultimately, is to be described by quantum theory. Quantum aspects of all there is, including space and time, may not be significant for many purposes, but are crucial for some. And so a quantum description of cosmology is required for a complete and consistent worldview. At any rate, even if we were not directly interested in regimes where quantum cosmology plays a role, a complete physical description could not stop at a stage before the whole universe is reached. Quantum theory is essential in the microphysics of particles, atoms, molecules, solids, white dwarfs and neutron stars. Why should one expect this ladder of scales to end at a certain size? If regimes are sufficiently violent and energetic, quantum effects are non-negligible even on scales of the whole cosmos; this is realized at least once in the history of the universe: at the big bang where the classical theory of general relativity would make energy densities diverge. 1.Lachieze-Rey, M., Luminet, J.P.: Phys. Rept. 254,135 (1995), gr-qc/9605010 2.BSDeWitt1967Phys. Rev.160511131967PhRv..160.1113D0158.4650410.1103/PhysRev.160.1113DeWitt, B.S.: Phys. Rev. 160(5), 1113 (1967) 3.Wiltshire, D.L.: In: Robson B., Visvanathan N., Woolcock W.S. (eds.) Cosmology: The Physics of the Universe, pp. 473-531. World Scientific, Singapore (1996). gr-qc/0101003 4.Isham C.J.: In: DeWitt, B.S., Stora, R. (eds.) Relativity, Groups and Topology II. Lectures Given at the 1983 Les Houches Summer School on Relativity, Groups and Topology, Elsevier Science Publishing Company (1986) 5.Klauder, J.: Int. J. Mod. Phys. D 12, 1769 (2003), gr-qc/0305067 6.Klauder, J.: Int. J. Geom. Meth. Mod. Phys. 3, 81 (2006), gr-qc/0507113 7.DGiulini1995Phys. Rev. D5110563013381161995PhRvD..51.5630G10.1103/PhysRevD.51.5630Giulini, D.: Phys. Rev. D 51(10), 5630 (1995) 8.Kiefer, C., Zeh, H.D.: Phys. Rev. D 51, 4145 (1995), gr-qc/9402036 9.WFBlythCJIsham1975Phys. Rev. D117684086991975PhRvD..11..768B10.1103/PhysRevD.11.768Blyth, W

  12. Spin network quantum simulator

    Energy Technology Data Exchange (ETDEWEB)

    Marzuoli, Annalisa; Rasetti, Mario

    2002-12-30

    We propose a general setting for a universal representation of the quantum structure on which quantum information stands, whose dynamical evolution (information manipulation) is based on angular momentum recoupling theory. Such scheme complies with the notion of 'quantum simulator' in the sense of Feynman, and is shown to be related with the topological quantum field theoretical approach to quantum computation.

  13. Quantum Steganography

    CERN Document Server

    Shaw, Bilal A

    2010-01-01

    Steganography is the process of hiding secret information by embedding it in an "innocent" message. We present protocols for hiding quantum information in a codeword of a quantum error-correcting code passing through a channel. Using either a shared classical secret key or shared entanglement the sender (Alice) disguises her information as errors in the channel. The receiver (Bob) can retrieve the hidden information, but an eavesdropper (Eve) with the power to monitor the channel, but without the secret key, cannot distinguish the message from channel noise. We analyze how difficult it is for Eve to detect the presence of secret messages, and estimate rates of steganographic communication and secret key consumption for certain protocols.

  14. Quantum interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Goernitz, T.; Weizsaecker, C.F.V.

    1987-10-01

    Four interpretations of quantum theory are compared: the Copenhagen interpretation (C.I.) with the additional assumption that the quantum description also applies to the mental states of the observer, and three recent ones, by Kochen, Deutsch, and Cramer. Since they interpret the same mathematical structure with the same empirical predictions, it is assumed that they formulate only different linguistic expressions of one identical theory. C.I. as a theory on human knowledge rests on a phenomenological description of time. It can be reconstructed from simple assumptions on predictions. Kochen shows that mathematically every composite system can be split into an object and an observer. Deutsch, with the same decomposition, describes futuric possibilities under the Everett term worlds. Cramer, using four-dimensional action at a distance (Wheeler-Feynman), describes all future events like past facts. All three can be described in the C.I. frame. The role of abstract nonlocality is discussed.

  15. Quantum Symmetry

    CERN Document Server

    Häring, Reto Andreas

    1993-01-01

    The representations of the observable algebra of a low dimensional quantum field theory form the objects of a braided tensor category. The search for gauge symmetry in the theory amounts to finding an algebra which has the same representation category. In this paper we try to establish that every quantum field theory satisfying some basic axioms posseses a weak quasi Hopf algebra as gauge symmetry. The first step is to construct a functor from the representation category to the category of finite dimensional vector spaces. Given such a functor we can use a generalized reconstruction theorem to find the symmetry algebra. It is shown how this symmetry algebra is used to build a gauge covariant field algebra and we investigate the question why this generality is necessary.

  16. Quantum psyche

    CERN Document Server

    Baaquie, Belal E; Demongeot, J; Galli-Carminati, Giuliana; Martin, F; Teodorani, Massimo

    2015-01-01

    At the end of the 19th century Sigmund Freud discovered that our acts and choices are not only decisions of our consciousness, but that they are also deeply determined by our unconscious (the so-called "Freudian unconscious"). During a long correspondence between them (1932-1958) Wolfgang Pauli and Carl Gustav Jung speculated that the unconscious could be a quantum system. This book is addressed both to all those interested in the new developments of the age-old enquiry in the relations between mind and matter, and also to the experts in quantum physics that are interested in a formalisation of this new approach. The description of the "Bilbao experiment" adds a very interesting experimental inquiry into the synchronicity effect in a group situation, linking theory to a quantifiable verification of these subtle effects. Cover design: "Entangled Minds". Riccardo Carminati Galli, 2014.

  17. Quantum Consciousness

    OpenAIRE

    Mould, Richard A

    1999-01-01

    In a previous paper, the author proposed a quantum mechanical interaction that would insure that the evolution of subjective states would parallel the evolution of biological states, as required by von Neumann's theory of measurement. The particular model for this interaction suggested an experiment that the author has now performed wih negative results. A modified model is outlined in this paper that preserves the desirable features of the original model, and is consistent with the experimen...

  18. Quantum Chromodynamics

    OpenAIRE

    Ecker, Gerhard

    2005-01-01

    After a brief historical review of the emergence of QCD as the quantum field theory of strong interactions, the basic notions of colour and gauge invariance are introduced leading to the QCD Lagrangian. The second lecture is devoted to perturbative QCD, from tree-level processes to higher-order corrections in renormalized perturbation theory, including jet production in e+ e- annihilation, hadronic tau decays and deep inelastic scattering. The final two lectures treat various aspects of QCD b...

  19. Experimental quantum forgery of quantum optical money

    Science.gov (United States)

    Bartkiewicz, Karol; Černoch, Antonín; Chimczak, Grzegorz; Lemr, Karel; Miranowicz, Adam; Nori, Franco

    2017-03-01

    Unknown quantum information cannot be perfectly copied (cloned). This statement is the bedrock of quantum technologies and quantum cryptography, including the seminal scheme of Wiesner's quantum money, which was the first quantum-cryptographic proposal. Surprisingly, to our knowledge, quantum money has not been tested experimentally yet. Here, we experimentally revisit the Wiesner idea, assuming a banknote to be an image encoded in the polarization states of single photons. We demonstrate that it is possible to use quantum states to prepare a banknote that cannot be ideally copied without making the owner aware of only unauthorized actions. We provide the security conditions for quantum money by investigating the physically-achievable limits on the fidelity of 1-to-2 copying of arbitrary sequences of qubits. These results can be applied as a security measure in quantum digital right management.

  20. Quantum Secure Direct Communication with Quantum Memory

    Science.gov (United States)

    Zhang, Wei; Ding, Dong-Sheng; Sheng, Yu-Bo; Zhou, Lan; Shi, Bao-Sen; Guo, Guang-Can

    2017-06-01

    Quantum communication provides an absolute security advantage, and it has been widely developed over the past 30 years. As an important branch of quantum communication, quantum secure direct communication (QSDC) promotes high security and instantaneousness in communication through directly transmitting messages over a quantum channel. The full implementation of a quantum protocol always requires the ability to control the transfer of a message effectively in the time domain; thus, it is essential to combine QSDC with quantum memory to accomplish the communication task. In this Letter, we report the experimental demonstration of QSDC with state-of-the-art atomic quantum memory for the first time in principle. We use the polarization degrees of freedom of photons as the information carrier, and the fidelity of entanglement decoding is verified as approximately 90%. Our work completes a fundamental step toward practical QSDC and demonstrates a potential application for long-distance quantum communication in a quantum network.

  1. Quantum Secure Direct Communication with Quantum Memory.

    Science.gov (United States)

    Zhang, Wei; Ding, Dong-Sheng; Sheng, Yu-Bo; Zhou, Lan; Shi, Bao-Sen; Guo, Guang-Can

    2017-06-02

    Quantum communication provides an absolute security advantage, and it has been widely developed over the past 30 years. As an important branch of quantum communication, quantum secure direct communication (QSDC) promotes high security and instantaneousness in communication through directly transmitting messages over a quantum channel. The full implementation of a quantum protocol always requires the ability to control the transfer of a message effectively in the time domain; thus, it is essential to combine QSDC with quantum memory to accomplish the communication task. In this Letter, we report the experimental demonstration of QSDC with state-of-the-art atomic quantum memory for the first time in principle. We use the polarization degrees of freedom of photons as the information carrier, and the fidelity of entanglement decoding is verified as approximately 90%. Our work completes a fundamental step toward practical QSDC and demonstrates a potential application for long-distance quantum communication in a quantum network.

  2. Quantum Locality?

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry

    2011-11-10

    Robert Griffiths has recently addressed, within the framework of a ‘consistent quantum theory’ (CQT) that he has developed, the issue of whether, as is often claimed, quantum mechanics entails a need for faster-than-light transfers of information over long distances. He argues, on the basis of his examination of certain arguments that claim to demonstrate the existence of such nonlocal influences, that such influences do not exist. However, his examination was restricted mainly to hidden-variable-based arguments that include in their premises some essentially classical-physics-type assumptions that are fundamentally incompatible with the precepts of quantum physics. One cannot logically prove properties of a system by attributing to the system properties alien to that system. Hence Griffiths’ rejection of hidden-variable-based proofs is logically warranted. Griffiths mentions the existence of a certain alternative proof that does not involve hidden variables, and that uses only macroscopically described observable properties. He notes that he had examined in his book proofs of this general kind, and concluded that they provide no evidence for nonlocal influences. But he did not examine the particular proof that he cites. An examination of that particular proof by the method specified by his ‘consistent quantum theory’ shows that the cited proof is valid within that restrictive framework. This necessary existence, within the ‘consistent’ framework, of long range essentially instantaneous influences refutes the claim made by Griffiths that his ‘consistent’ framework is superior to the orthodox quantum theory of von Neumann because it does not entail instantaneous influences. An added section responds to Griffiths’ reply, which cites a litany of ambiguities that seem to restrict, devastatingly, the scope of his CQT formalism, apparently to buttress his claim that my use of that formalism to validate the nonlocality theorem is flawed. But the

  3. Elementary quantum chemistry

    CERN Document Server

    Pilar, Frank L

    2003-01-01

    Useful introductory course and reference covers origins of quantum theory, Schrödinger wave equation, quantum mechanics of simple systems, electron spin, quantum states of atoms, Hartree-Fock self-consistent field method, more. 1990 edition.

  4. Homomorphisms of quantum groups

    CERN Document Server

    Meyer, Ralf; Woronowicz, Stanisław Lech

    2010-01-01

    We introduce some equivalent notions of homomorphisms between quantum groups that behave well with respect to duality of quantum groups. Our equivalent definitions are based on bicharacters, coactions, and universal quantum groups, respectively.

  5. Quantum probability and quantum decision-making.

    Science.gov (United States)

    Yukalov, V I; Sornette, D

    2016-01-13

    A rigorous general definition of quantum probability is given, which is valid not only for elementary events but also for composite events, for operationally testable measurements as well as for inconclusive measurements, and also for non-commuting observables in addition to commutative observables. Our proposed definition of quantum probability makes it possible to describe quantum measurements and quantum decision-making on the same common mathematical footing. Conditions are formulated for the case when quantum decision theory reduces to its classical counterpart and for the situation where the use of quantum decision theory is necessary.

  6. Quantum conductance in silicon quantum wires

    CERN Document Server

    Bagraev, N T; Klyachkin, L E; Malyarenko, A M; Gehlhoff, W; Ivanov, V K; Shelykh, I A

    2002-01-01

    The results of investigations of electron and hole quantum conductance staircase in silicon quantum wires are presented. The characteristics of self-ordering quantum wells of n- and p-types, which from on the silicon (100) surface in the nonequilibrium boron diffusion process, are analyzed. The results of investigations of the quantum conductance as the function of temperature, carrier concentration and modulation degree of silicon quantum wires are given. It is found out, that the quantum conductance of the one-dimensional channels is observed, for the first time, at an elevated temperature (T >= 77 K)

  7. Quantum coherence and correlations in quantum system

    Science.gov (United States)

    Xi, Zhengjun; Li, Yongming; Fan, Heng

    2015-01-01

    Criteria of measure quantifying quantum coherence, a unique property of quantum system, are proposed recently. In this paper, we first give an uncertainty-like expression relating the coherence and the entropy of quantum system. This finding allows us to discuss the relations between the entanglement and the coherence. Further, we discuss in detail the relations among the coherence, the discord and the deficit in the bipartite quantum system. We show that, the one-way quantum deficit is equal to the sum between quantum discord and the relative entropy of coherence of measured subsystem. PMID:26094795

  8. Dissipative tunneling in structures with quantum dots and quantum molecules

    OpenAIRE

    Dahnovsky, Yu. I.; Krevchik, V. D.; Semenov, M. B.; Yamamoto, K.; Zhukovsky, V. Ch.; Aringazin, A. K.; Kudryashov, E. I.; Mayorov, V. G.

    2005-01-01

    The problem of tunneling control in systems "quantum dot - quantum well" (as well as "quantum dot - quantum dot" or quantum molecule) and "quantum dot - bulk contact" is studied as a quantum tunneling with dissipation process in the semiclassical (instanton) approximation. For these systems temperature and correlation between a quantum dot radius and a quantum well width (or another quantum dot radius) are considered to be control parameters. The condition for a single electron blockade is fo...

  9. Constructing quantum codes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Quantum error correcting codes are indispensable for quantum information processing and quantum computation.In 1995 and 1996,Shor and Steane gave first several examples of quantum codes from classical error correcting codes.The construction of efficient quantum codes is now an active multi-discipline research field.In this paper we review the known several constructions of quantum codes and present some examples.

  10. Quantum Message Distribution

    Institute of Scientific and Technical Information of China (English)

    LUO Ming-Xing; CHEN Xiu-Bo; DENG Yun; Yang Yi-Xian

    2013-01-01

    The semiquantum techniques have been explored recently to bridge the classical communications and the quantum communications.In this paper,we present one scheme to distribute the messages from one quantum participate to one weak quantum participate who can only measure the quantum states.It is proved to be robust by combining the classical coding encryption,quantum coding and other quantum techniques.

  11. Quantum Correlations Evolution Asymmetry in Quantum Channels

    Science.gov (United States)

    Li, Meng; Huang, Yun-Feng; Guo, Guang-Can

    2017-03-01

    It was demonstrated that the entanglement evolution of a specially designed quantum state in the bistochastic channel is asymmetric. In this work, we generalize the study of the quantum correlations, including entanglement and quantum discord, evolution asymmetry to various quantum channels. We found that the asymmetry of entanglement and quantum discord only occurs in some special quantum channels, and the behavior of the entanglement evolution may be quite different from the behavior of the quantum discord evolution. To quantum entanglement, in some channels it decreases monotonously with the increase of the quantum channel intensity. In some other channels, when we increase the intensity of the quantum channel, it decreases at first, then keeps zero for some time, and then rises up. To quantum discord, the evolution becomes more complex and you may find that it evolutes unsmoothly at some points. These results illustrate the strong dependence of the quantum correlations evolution on the property of the quantum channels. Supported by the National Natural Science Foundation of China under Grant Nos. 61327901, 61490711, 61225025, 11474268, and the Fundamental Research Funds for the Central Universities under Grant No. WK2470000018

  12. Interference of Quantum Market Strategies

    CERN Document Server

    Piotrowski, E W; Syska, J

    2003-01-01

    Recent development in quantum computation and quantum information theory allows to extend the scope of game theory for the quantum world. The paper is devoted to the analysis of interference of quantum strategies in quantum market games.

  13. Single semiconductor quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Michler, Peter (ed.) [Stuttgart Univ. (Germany). Inst. fuer Halbleiteroptik und Funktionelle Grenzflaechen

    2009-07-01

    This book reviews recent advances in the exciting and rapidly growing field of semiconductor quantum dots via contributions from some of the most prominent researchers in the scientific community. Special focus is given to optical, quantum optical, and spin properties of single quantum dots due to their potential applications in devices operating with single electron spins and/or single photons. This includes single and coupled quantum dots in external fields, cavity-quantum electrodynamics, and single and entangled photon pair generation. Single Semiconductor Quantum Dots also addresses growth techniques to allow for a positioned nucleation of dots as well as applications of quantum dots in quantum information technologies. (orig.)

  14. Quantum information processing in nanostructures Quantum optics; Quantum computing

    CERN Document Server

    Reina-Estupinan, J H

    2002-01-01

    Since information has been regarded os a physical entity, the field of quantum information theory has blossomed. This brings novel applications, such as quantum computation. This field has attracted the attention of numerous researchers with backgrounds ranging from computer science, mathematics and engineering, to the physical sciences. Thus, we now have an interdisciplinary field where great efforts are being made in order to build devices that should allow for the processing of information at a quantum level, and also in the understanding of the complex structure of some physical processes at a more basic level. This thesis is devoted to the theoretical study of structures at the nanometer-scale, 'nanostructures', through physical processes that mainly involve the solid-state and quantum optics, in order to propose reliable schemes for the processing of quantum information. Initially, the main results of quantum information theory and quantum computation are briefly reviewed. Next, the state-of-the-art of ...

  15. From Quantum Cheating to Quantum Security

    CERN Document Server

    Gottesman, D; Gottesman, Daniel; Lo, Hoi-Kwong

    2000-01-01

    For thousands of years, code-makers and code-breakers have been competing for supremacy. Their arsenals may soon include a powerful new weapon: quantum mechanics. We give an overview of quantum cryptology as of November 2000.

  16. Quantum Communication Complexity of Quantum Authentication Protocols

    CERN Document Server

    Guedes, Elloá B

    2011-01-01

    In order to perform Quantum Cryptography procedures it is often essencial to ensure that the parties of the communication are authentic. Such task is accomplished by quantum authentication protocols which are distributed algorithms based on the intrinsic properties of Quantum Mechanics. The choice of an authentication protocol must consider that quantum states are very delicate and that the channel is subject to eavesdropping. However, even in face of the various existing definitions of quantum authentication protocols in the literature, little is known about them in this perspective, and this lack of knowledge may unfavor comparisons and wise choices. In the attempt to overcome this limitation, in the present work we aim at showing an approach to evaluate quantum authentication protocols based on the determination of their quantum communication complexity. Based on our investigation, no similar methods to analyze quantum authentication protocols were found in the literature. Pursuing this further, our approa...

  17. Quantum mechanics

    CERN Document Server

    Mandl, Franz

    1992-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A. C. Phillips Computing for Scient

  18. Quantum electrodynamics

    CERN Document Server

    1990-01-01

    Quantum electrodynamics is an essential building block and an integral part of the gauge theory of unified electromagnetic, weak, and strong interactions, the so-called standard model. Its failure or breakdown at some level would have a most profound impact on the theoretical foundations of elementary particle physics as a whole. Thus the validity of QED has been the subject of intense experimental tests over more than 40 years of its history. This volume presents an up-to-date review of high precision experimental tests of QED together with comprehensive discussion of required theoretical wor

  19. Quantum Associative Memory

    CERN Document Server

    Ventura, D; Ventura, Dan; Martinez, Tony

    1998-01-01

    This paper combines quantum computation with classical neural network theory to produce a quantum computational learning algorithm. Quantum computation uses microscopic quantum level effects to perform computational tasks and has produced results that in some cases are exponentially faster than their classical counterparts. The unique characteristics of quantum theory may also be used to create a quantum associative memory with a capacity exponential in the number of neurons. This paper combines two quantum computational algorithms to produce such a quantum associative memory. The result is an exponential increase in the capacity of the memory when compared to traditional associative memories such as the Hopfield network. The paper covers necessary high-level quantum mechanical and quantum computational ideas and introduces a quantum associative memory. Theoretical analysis proves the utility of the memory, and it is noted that a small version should be physically realizable in the near future.

  20. Quantum information theory

    CERN Document Server

    Nielsen, M A

    1998-01-01

    Quantum information theory is the study of the achievable limits of information processing within quantum mechanics. Many different types of information can be accommodated within quantum mechanics, including classical information, coherent quantum information, and entanglement. Exploring the rich variety of capabilities allowed by these types of information is the subject of quantum information theory, and of this Dissertation. In particular, I demonstrate several novel limits to the information processing ability of quantum mechanics. Results of especial interest include: the demonstration of limitations to the class of measurements which may be performed in quantum mechanics; a capacity theorem giving achievable limits to the transmission of classical information through a two-way noiseless quantum channel; resource bounds on distributed quantum computation; a new proof of the quantum noiseless channel coding theorem; an information-theoretic characterization of the conditions under which quantum error-cor...

  1. Quantum Steganography and Quantum Error-Correction

    Science.gov (United States)

    Shaw, Bilal A.

    2010-01-01

    Quantum error-correcting codes have been the cornerstone of research in quantum information science (QIS) for more than a decade. Without their conception, quantum computers would be a footnote in the history of science. When researchers embraced the idea that we live in a world where the effects of a noisy environment cannot completely be…

  2. Quantum Steganography and Quantum Error-Correction

    Science.gov (United States)

    Shaw, Bilal A.

    2010-01-01

    Quantum error-correcting codes have been the cornerstone of research in quantum information science (QIS) for more than a decade. Without their conception, quantum computers would be a footnote in the history of science. When researchers embraced the idea that we live in a world where the effects of a noisy environment cannot completely be…

  3. Quantum Cybernetics and Complex Quantum Systems Science - A Quantum Connectionist Exploration

    OpenAIRE

    Gonçalves, Carlos Pedro

    2014-01-01

    Quantum cybernetics and its connections to complex quantum systems science is addressed from the perspective of complex quantum computing systems. In this way, the notion of an autonomous quantum computing system is introduced in regards to quantum artificial intelligence, and applied to quantum artificial neural networks, considered as autonomous quantum computing systems, which leads to a quantum connectionist framework within quantum cybernetics for complex quantum computing systems. Sever...

  4. Quantum Cybernetics and Complex Quantum Systems Science - A Quantum Connectionist Exploration

    OpenAIRE

    Gonçalves, Carlos Pedro

    2014-01-01

    Quantum cybernetics and its connections to complex quantum systems science is addressed from the perspective of complex quantum computing systems. In this way, the notion of an autonomous quantum computing system is introduced in regards to quantum artificial intelligence, and applied to quantum artificial neural networks, considered as autonomous quantum computing systems, which leads to a quantum connectionist framework within quantum cybernetics for complex quantum computing systems. Sever...

  5. Quantum algorithms for quantum field theories.

    Science.gov (United States)

    Jordan, Stephen P; Lee, Keith S M; Preskill, John

    2012-06-01

    Quantum field theory reconciles quantum mechanics and special relativity, and plays a central role in many areas of physics. We developed a quantum algorithm to compute relativistic scattering probabilities in a massive quantum field theory with quartic self-interactions (φ(4) theory) in spacetime of four and fewer dimensions. Its run time is polynomial in the number of particles, their energy, and the desired precision, and applies at both weak and strong coupling. In the strong-coupling and high-precision regimes, our quantum algorithm achieves exponential speedup over the fastest known classical algorithm.

  6. Quantum State Tomography and Quantum Games

    Institute of Scientific and Technical Information of China (English)

    Ahmad Nawaz

    2012-01-01

    A technique is developed for single qubit quantum state tomography using the mathematical setup of generalized quantization scheme for games. In this technique,Alice sends an unknown pure quantum state to Bob who appends it with |0><0| and then applies the unitary operators on the appended quantum state and finds the payoffs for Alice and himself.It is shown that for a particular set of unitary operators,these payoffs are equal to Stokes parameters for an unknown quantum state.In this way an unknown quantum state can be measured and reconstructed.Strictly speaking,this technique is not a game as no strategic competitions are involved.

  7. Quantum Gates and Circuits

    CERN Document Server

    Di Vincenzo, D P

    1997-01-01

    A historical review is given of the emergence of the idea of the quantum logic gate from the theory of reversible Boolean gates. I highlight the quantum XOR or controlled NOT as the fundamental two-bit gate for quantum computation. This gate plays a central role in networks for quantum error correction.

  8. Controlling Quantum Chaos

    Science.gov (United States)

    Pokharel, Bibek; Pattanayak, Arjendu

    2014-05-01

    We have recently computed Lyapunov exponents describing the chaotic behavior of the quantum trajectories of an open quantum nonlinear oscillator using the Quantum State Diffusion formalism. We have seen several interesting features as a function of changing system parameters. We report on progress towards controlling the observed quantum chaotic behavior using the classical Ott-Grebogi-Yorke protocol.

  9. Advanced quantum communication systems

    Science.gov (United States)

    Jeffrey, Evan Robert

    Quantum communication provides several examples of communication protocols which cannot be implemented securely using only classical communication. Currently, the most widely known of these is quantum cryptography, which allows secure key exchange between parties sharing a quantum channel subject to an eavesdropper. This thesis explores and extends the realm of quantum communication. Two new quantum communication protocols are described. The first is a new form of quantum cryptography---relativistic quantum cryptography---which increases communication efficiency by exploiting a relativistic bound on the power of an eavesdropper, in addition to the usual quantum mechanical restrictions intrinsic to quantum cryptography. By doing so, we have observed over 170% improvement in communication efficiency over a similar protocol not utilizing relativity. A second protocol, Quantum Orienteering, allows two cooperating parties to communicate a specific direction in space. This application shows the possibility of using joint measurements, or projections onto an entangled state, in order to extract the maximum useful information from quantum bits. For two-qubit communication, the maximal fidelity of communication using only separable operations is 73.6%, while joint measurements can improve the efficiency to 78.9%. In addition to implementing these protocols, we have improved several resources for quantum communication and quantum computing. Specifically, we have developed improved sources of polarization-entangled photons, a low-loss quantum memory for polarization qubits, and a quantum random number generator. These tools may be applied to a wide variety of future quantum and classical information systems.

  10. Quantum Cat's Dilemma

    CERN Document Server

    Makowski, M; Makowski, Marcin; Piotrowski, Edward W.

    2005-01-01

    We study a quantum version of the sequential game illustrating problems connected with making rational decisions. We compare the results that the two models (quantum and classical) yield. In the quantum model intransitivity gains importance significantly. We argue that the quantum model describes our spontaneously shown preferences more precisely than the classical model, as these preferences are often intransitive.

  11. Quantum Entanglement and Teleportation

    OpenAIRE

    2011-01-01

    Even Einstein has to be wrong sometimes. However, when Einstein was wrong he created a 70 year debate about the strange behavior of quantum mechanics. His debate helped prove topics such as the indeterminacy of particle states, quantum entanglement, and a rather clever use of quantum entanglement known as quantum teleportation.

  12. Monogamy of Quantum Discord

    CERN Document Server

    Ren, Xi-Jun

    2011-01-01

    Quantum discord is not monogamous. We consider a pure tripartite state and show that the monogamy inequality of quantum discord is related with a relation between quantum mutual information and entanglement of formation of two parties. The upper bounds of quantum discord and classical correlation are presented. Our results relate the correlations present in a bipartite system with the monogamy or polygamy property of quantum discord in a tripartite pure state. The relation, which is about three important concepts in quantum information theory, quantum discord, entanglement of formation and mutual information, may provide new insights for their further understanding.

  13. Quantum feedback channels

    CERN Document Server

    Bowen, G

    2002-01-01

    In classical information theory the capacity of a noisy communication channel cannot be increased by the use of feedback. In quantum information theory the no-cloning theorem means that noiseless copying and feedback of quantum information cannot be achieved. In this paper, quantum feedback is defined as the unlimited use of a noiseless quantum channel from receiver to sender. Given such quantum feedback, it is shown to provide no increase in the entanglement-assisted capacities of a noisy quantum channel, in direct analogy to the classical case. It is also shown that in various cases of non-assisted capacities, feedback can increase the capacity of many quantum channels.

  14. A quantum-quantum Metropolis algorithm.

    Science.gov (United States)

    Yung, Man-Hong; Aspuru-Guzik, Alán

    2012-01-17

    The classical Metropolis sampling method is a cornerstone of many statistical modeling applications that range from physics, chemistry, and biology to economics. This method is particularly suitable for sampling the thermal distributions of classical systems. The challenge of extending this method to the simulation of arbitrary quantum systems is that, in general, eigenstates of quantum Hamiltonians cannot be obtained efficiently with a classical computer. However, this challenge can be overcome by quantum computers. Here, we present a quantum algorithm which fully generalizes the classical Metropolis algorithm to the quantum domain. The meaning of quantum generalization is twofold: The proposed algorithm is not only applicable to both classical and quantum systems, but also offers a quantum speedup relative to the classical counterpart. Furthermore, unlike the classical method of quantum Monte Carlo, this quantum algorithm does not suffer from the negative-sign problem associated with fermionic systems. Applications of this algorithm include the study of low-temperature properties of quantum systems, such as the Hubbard model, and preparing the thermal states of sizable molecules to simulate, for example, chemical reactions at an arbitrary temperature.

  15. Secure quantum signatures using insecure quantum channels

    Science.gov (United States)

    Amiri, Ryan; Wallden, Petros; Kent, Adrian; Andersson, Erika

    2016-03-01

    Digital signatures are widely used in modern communication to guarantee authenticity and transferability of messages. The security of currently used classical schemes relies on computational assumptions. We present a quantum signature scheme that does not require trusted quantum channels. We prove that it is unconditionally secure against the most general coherent attacks, and show that it requires the transmission of significantly fewer quantum states than previous schemes. We also show that the quantum channel noise threshold for our scheme is less strict than for distilling a secure key using quantum key distribution. This shows that "direct" quantum signature schemes can be preferable to signature schemes relying on secret shared keys generated using quantum key distribution.

  16. Quantum engineering of continuous variable quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Sabuncu, Metin

    2009-10-29

    Quantum information with continuous variables is a field attracting increasing attention recently. In continuous variable quantum information one makes use of the continuous information encoded into the quadrature of a quantized light field instead of binary quantities such as the polarization state of a single photon. This brand new research area is witnessing exciting theoretical and experimental achievements such as teleportation, quantum computation and quantum error correction. The rapid development of the field is mainly due higher optical data rates and the availability of simple and efficient manipulation tools in continuous-variable quantum information processing. We in this thesis extend the work in continuous variable quantum information processing and report on novel experiments on amplification, cloning, minimal disturbance and noise erasure protocols. The promising results we obtain in these pioneering experiments indicate that the future of continuous variable quantum information is bright and many advances can be foreseen. (orig.)

  17. Uncertainty under quantum measures and quantum memory

    Science.gov (United States)

    Xiao, Yunlong; Jing, Naihuan; Li-Jost, Xianqing

    2017-04-01

    The uncertainty principle restricts potential information one gains about physical properties of the measured particle. However, if the particle is prepared in entanglement with a quantum memory, the corresponding entropic uncertainty relation will vary. Based on the knowledge of correlations between the measured particle and quantum memory, we have investigated the entropic uncertainty relations for two and multiple measurements and generalized the lower bounds on the sum of Shannon entropies without quantum side information to those that allow quantum memory. In particular, we have obtained generalization of Kaniewski-Tomamichel-Wehner's bound for effective measures and majorization bounds for noneffective measures to allow quantum side information. Furthermore, we have derived several strong bounds for the entropic uncertainty relations in the presence of quantum memory for two and multiple measurements. Finally, potential applications of our results to entanglement witnesses are discussed via the entropic uncertainty relation in the absence of quantum memory.

  18. Quantum signatures of chaos or quantum chaos?

    Energy Technology Data Exchange (ETDEWEB)

    Bunakov, V. E., E-mail: bunakov@VB13190.spb.edu [St. Petersburg State University (Russian Federation)

    2016-11-15

    A critical analysis of the present-day concept of chaos in quantum systems as nothing but a “quantum signature” of chaos in classical mechanics is given. In contrast to the existing semi-intuitive guesses, a definition of classical and quantum chaos is proposed on the basis of the Liouville–Arnold theorem: a quantum chaotic system featuring N degrees of freedom should have M < N independent first integrals of motion (good quantum numbers) specified by the symmetry of the Hamiltonian of the system. Quantitative measures of quantum chaos that, in the classical limit, go over to the Lyapunov exponent and the classical stability parameter are proposed. The proposed criteria of quantum chaos are applied to solving standard problems of modern dynamical chaos theory.

  19. Introduction to topological quantum matter & quantum computation

    CERN Document Server

    Stanescu, Tudor D

    2017-01-01

    What is -topological- about topological quantum states? How many types of topological quantum phases are there? What is a zero-energy Majorana mode, how can it be realized in a solid state system, and how can it be used as a platform for topological quantum computation? What is quantum computation and what makes it different from classical computation? Addressing these and other related questions, Introduction to Topological Quantum Matter & Quantum Computation provides an introduction to and a synthesis of a fascinating and rapidly expanding research field emerging at the crossroads of condensed matter physics, mathematics, and computer science. Providing the big picture, this book is ideal for graduate students and researchers entering this field as it allows for the fruitful transfer of paradigms and ideas amongst different areas, and includes many specific examples to help the reader understand abstract and sometimes challenging concepts. It explores the topological quantum world beyond the well-know...

  20. Role of quantum discord in quantum communication

    CERN Document Server

    Madhok, Vaibhav

    2011-01-01

    Positivity of quantum discord is shown to be equivalent to the strong sub additivity of the Von-Nuemann entropy. This leads to a connection between the mother protocol of quantum information theory [A. Abeyesinghe, I. Devetak, P. Hayden, and A. Winter, Proc. R. Soc. A 465, 2537, (2009)] and quantum discord. We exploit this to show that quantum discord is a measure coherence in the performance of the mother protocol. Since the mother protocol is a unification of an important class of problems (those that are bipartite, unidirectional and memoryless), we show quantum discord to be a measure of coherence in these protocols. Our work generalizes an earlier operational interpretation of quantum discord provided in terms of quantum state merging [V. Madhok and A. Datta, Phys. Rev. A 83, 032323, (2011)].

  1. Quantum Robots Plus Environments

    CERN Document Server

    Benioff, P

    1998-01-01

    A quantum robot is a mobile quantum system including an on bord quantum computer and ancillary systems, that interact with an environment of quantum systems. Quantum robots carry out tasks whose goals include carrying out measurements and physical experiments on the environment. Environments considered so far in the literature: oracles, data bases, and quantum registers, are shown to be special cases of environments considered here. It is noted that quantum robots should include a quantum computer and cannot be simply a multistate head. A model is discussed in which each task, as a sequence of computation and action phases, is described by a unitary step operator. Overall system dynamics is described in terms of a Feynman sum over paths of completed computation and action phases. A simple task example, measuring the distance between the quantum robot and a particle on a 1D space lattice, with quantum phase path and time duration dispersion present, is analyzed.

  2. Quantum mechanics symmetries

    CERN Document Server

    Greiner, Walter

    1989-01-01

    "Quantum Dynamics" is a major survey of quantum theory based on Walter Greiner's long-running and highly successful courses at the University of Frankfurt. The key to understanding in quantum theory is to reinforce lecture attendance and textual study by working through plenty of representative and detailed examples. Firm belief in this principle led Greiner to develop his unique course and to transform it into a remarkable and comprehensive text. The text features a large number of examples and exercises involving many of the most advanced topics in quantum theory. These examples give practical and precise demonstrations of how to use the often subtle mathematics behind quantum theory. The text is divided into five volumes: Quantum Mechanics I - An Introduction, Quantum Mechanics II - Symmetries, Relativistic Quantum Mechanics, Quantum Electrodynamics, Gauge Theory of Weak Interactions. These five volumes take the reader from the fundamental postulates of quantum mechanics up to the latest research in partic...

  3. Quantum optical waveform conversion

    CERN Document Server

    Kielpinski, D; Wiseman, HM

    2010-01-01

    Currently proposed architectures for long-distance quantum communication rely on networks of quantum processors connected by optical communications channels [1,2]. The key resource for such networks is the entanglement of matter-based quantum systems with quantum optical fields for information transmission. The optical interaction bandwidth of these material systems is a tiny fraction of that available for optical communication, and the temporal shape of the quantum optical output pulse is often poorly suited for long-distance transmission. Here we demonstrate that nonlinear mixing of a quantum light pulse with a spectrally tailored classical field can compress the quantum pulse by more than a factor of 100 and flexibly reshape its temporal waveform, while preserving all quantum properties, including entanglement. Waveform conversion can be used with heralded arrays of quantum light emitters to enable quantum communication at the full data rate of optical telecommunications.

  4. Quantum chimera states

    Energy Technology Data Exchange (ETDEWEB)

    Viennot, David, E-mail: david.viennot@utinam.cnrs.fr; Aubourg, Lucile

    2016-02-15

    We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered dynamics. For the quantum analogue, the chimera behaviour deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of our quantum chimera system. The quantum chimera concept is novel and induces new perspectives concerning the entanglement of multipartite systems. - Highlights: • We propose a spin chain model with long range couplings having purely quantum states similar to the classical chimera states. • The quantum chimera states are characterized by the coexistence of strongly entangled and non-entangled spins in the same chain. • The quantum chimera states present some characteristics of quantum chaos.

  5. Quantum key management

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

    2016-11-29

    Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

  6. Quantum Information An Introduction

    CERN Document Server

    Hayashi, Masahito

    2006-01-01

    Recently, quantum information theory has been developing through a fusion of results from various research fields. This requires that understanding of basic results on diverse topics, and derived from different disciplinary perspectives, is required for appreciating the overall picture. Intended to merge key topics from both the information-theoretic and quantum- mechanical viewpoints, this graduate-level textbook provides a unified viewpoint of quantum information theory and lucid explanations of those basic results, so that the reader fundamentally grasps advances and challenges. For example, advanced topics in quantum communication such as quantum teleportation, superdense coding, quantum state transmission (quantum error-correction), and quantum encryption especially benefit from this unified approach. Unlike earlier treatments, the text requires knowledge of only linear algebra, probability theory, and quantum mechanics, while it treats the topics of quantum hypothesis testing and the discrimination of q...

  7. Quantum key management

    Science.gov (United States)

    Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

    2016-11-29

    Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

  8. Randomness: Quantum versus classical

    Science.gov (United States)

    Khrennikov, Andrei

    2016-05-01

    Recent tremendous development of quantum information theory has led to a number of quantum technological projects, e.g. quantum random generators. This development had stimulated a new wave of interest in quantum foundations. One of the most intriguing problems of quantum foundations is the elaboration of a consistent and commonly accepted interpretation of a quantum state. Closely related problem is the clarification of the notion of quantum randomness and its interrelation with classical randomness. In this short review, we shall discuss basics of classical theory of randomness (which by itself is very complex and characterized by diversity of approaches) and compare it with irreducible quantum randomness. We also discuss briefly “digital philosophy”, its role in physics (classical and quantum) and its coupling to the information interpretation of quantum mechanics (QM).

  9. Quantum Histories

    CERN Document Server

    Kent, A

    1998-01-01

    There are good motivations for considering some type of quantum histories formalism. Several possible formalisms are known, defined by different definitions of event and by different selection criteria for sets of histories. These formalisms have a natural interpretation, according to which nature somehow chooses one set of histories from among those allowed, and then randomly chooses to realise one history from that set; other interpretations are possible, but their scientific implications are essentially the same. The selection criteria proposed to date are reasonably natural, and certainly raise new questions. For example, the validity of ordering inferences which we normally take for granted --- such as that a particle in one region is necessarily in a larger region containing it --- depends on whether or not our history respects the criterion of ordered consistency, or merely consistency. However, the known selection criteria, including consistency and medium decoherence, are very weak. It is not possibl...

  10. Quantum economics

    Directory of Open Access Journals (Sweden)

    Vukotić Veselin

    2011-01-01

    Full Text Available The globalization is breaking-down the idea of national state, which was the base for the development of economic theory which is dominant today. Global economic crisis puts emphasis on limited possibilities of national governments in solving economic problems and general problems of society. Does it also mean that globalization and global economic crisis points out the need to think about new economic theory and new understanding of economics? In this paper I will argue that globalization reveals the need to change dominant economic paradigm - from traditional economic theory (mainstream with macroeconomic stability as the goal of economic policy, to the “quantum economics“, which is based on “economic quantum” and immanent to the increase of wealth (material and non-material of every individual in society and promoting set of values immanent to the wealth increase as the goal of economic policy. Practically the question is how we can use global market for our development!

  11. Quantum information causality

    OpenAIRE

    Pitalúa-García, Damián

    2012-01-01

    How much information can a transmitted physical system fundamentally communicate? We introduce the principle of quantum information causality, which states the maximum amount of quantum information that a quantum system can communicate as a function of its dimension, independently of any previously shared quantum physical resources. We present a new quantum information task, whose success probability is upper bounded by the new principle, and show that an optimal strategy to perform it combin...

  12. Quantum physics for beginners

    CERN Document Server

    Ficek, Zbigniew

    2016-01-01

    The textbook introduces students to the main ideas of quantum physics and the basic mathematical methods and techniques used in the fields of advanced quantum physics, atomic physics, laser physics, nanotechnology, quantum chemistry, and theoretical mathematics. The textbook explains how microscopic objects (particles) behave in unusual ways, giving rise to what's called quantum effects. It contains a wide range of tutorial problems from simple confidence-builders to fairly challenging exercises that provide adequate understanding of the basic concepts of quantum physics.

  13. Broadband Quantum Cryptography

    CERN Document Server

    Rogers, Daniel

    2010-01-01

    Quantum cryptography is a rapidly developing field that draws from a number of disciplines, from quantum optics to information theory to electrical engineering. By combining some fundamental quantum mechanical principles of single photons with various aspects of information theory, quantum cryptography represents a fundamental shift in the basis for security from numerical complexity to the fundamental physical nature of the communications channel. As such, it promises the holy grail of data security: theoretically unbreakable encryption. Of course, implementing quantum cryptography in real br

  14. Quantum computing classical physics.

    Science.gov (United States)

    Meyer, David A

    2002-03-15

    In the past decade, quantum algorithms have been found which outperform the best classical solutions known for certain classical problems as well as the best classical methods known for simulation of certain quantum systems. This suggests that they may also speed up the simulation of some classical systems. I describe one class of discrete quantum algorithms which do so--quantum lattice-gas automata--and show how to implement them efficiently on standard quantum computers.

  15. Quantum Virtual Machine (QVM)

    Energy Technology Data Exchange (ETDEWEB)

    2016-11-18

    There is a lack of state-of-the-art HPC simulation tools for simulating general quantum computing. Furthermore, there are no real software tools that integrate current quantum computers into existing classical HPC workflows. This product, the Quantum Virtual Machine (QVM), solves this problem by providing an extensible framework for pluggable virtual, or physical, quantum processing units (QPUs). It enables the execution of low level quantum assembly codes and returns the results of such executions.

  16. Quantum Information Theory

    OpenAIRE

    Nielsen, M. A.

    2000-01-01

    Quantum information theory is the study of the achievable limits of information processing within quantum mechanics. Many different types of information can be accommodated within quantum mechanics, including classical information, coherent quantum information, and entanglement. Exploring the rich variety of capabilities allowed by these types of information is the subject of quantum information theory, and of this Dissertation. In particular, I demonstrate several novel limits to the informa...

  17. Quantum correlations and measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sperling, Jan

    2015-07-16

    The present thesis is a state of the art report on the characterization techniques and measurement strategies to verify quantum correlations. I mainly focus on research which has been performed in the theoretical quantum optics group at the University of Rostock during the last few years. The results include theoretical findings and analysis of experimental studies of radiation fields. We investigate the verification of quantum properties, the quantification of these quantum effects, and the characterization of quantum optical detector systems.

  18. On Quantum Algorithms

    CERN Document Server

    Cleve, R; Henderson, L; Macchiavello, C; Mosca, M

    1998-01-01

    Quantum computers use the quantum interference of different computational paths to enhance correct outcomes and suppress erroneous outcomes of computations. In effect, they follow the same logical paradigm as (multi-particle) interferometers. We show how most known quantum algorithms, including quantum algorithms for factorising and counting, may be cast in this manner. Quantum searching is described as inducing a desired relative phase between two eigenvectors to yield constructive interference on the sought elements and destructive interference on the remaining terms.

  19. Quantum Random Number Generators

    OpenAIRE

    Herrero-Collantes, Miguel; Garcia-Escartin, Juan Carlos

    2016-01-01

    Random numbers are a fundamental resource in science and engineering with important applications in simulation and cryptography. The inherent randomness at the core of quantum mechanics makes quantum systems a perfect source of entropy. Quantum random number generation is one of the most mature quantum technologies with many alternative generation methods. We discuss the different technologies in quantum random number generation from the early devices based on radioactive decay to the multipl...

  20. IETS and quantum interference

    DEFF Research Database (Denmark)

    Jørgensen, Jacob Lykkebo; Gagliardi, Alessio; Pecchia, Alessandro

    2014-01-01

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low...... suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference....

  1. Probabilistic Cloning and Quantum Computation

    Institute of Scientific and Technical Information of China (English)

    GAO Ting; YAN Feng-Li; WANG Zhi-Xi

    2004-01-01

    @@ We discuss the usefulness of quantum cloning and present examples of quantum computation tasks for which the cloning offers an advantage which cannot be matched by any approach that does not resort to quantum cloning.In these quantum computations, we need to distribute quantum information contained in the states about which we have some partial information. To perform quantum computations, we use a state-dependent probabilistic quantum cloning procedure to distribute quantum information in the middle of a quantum computation.

  2. Entanglement, quantum phase transitions and quantum algorithms

    CERN Document Server

    Orus, R

    2006-01-01

    The work that we present in this thesis tries to be at the crossover of quantum information science, quantum many-body physics, and quantum field theory. We use tools from these three fields to analyze problems that arise in the interdisciplinary intersection. More concretely, in Chapter 1 we consider the irreversibility of renormalization group flows from a quantum information perspective by using majorization theory and conformal field theory. In Chapter 2 we compute the entanglement of a single copy of a bipartite quantum system for a variety of models by using techniques from conformal field theory and Toeplitz matrices. The entanglement entropy of the so-called Lipkin-Meshkov-Glick model is computed in Chapter 3, showing analogies with that of (1+1)-dimensional quantum systems. In Chapter 4 we apply the ideas of scaling of quantum correlations in quantum phase transitions to the study of quantum algorithms, focusing on Shor's factorization algorithm and quantum algorithms by adiabatic evolution solving a...

  3. Expected number of quantum channels in quantum networks

    Science.gov (United States)

    Chen, Xi; Wang, He-Ming; Ji, Dan-Tong; Mu, Liang-Zhu; Fan, Heng

    2015-07-01

    Quantum communication between nodes in quantum networks plays an important role in quantum information processing. Here, we proposed the use of the expected number of quantum channels as a measure of the efficiency of quantum communication for quantum networks. This measure quantified the amount of quantum information that can be teleported between nodes in a quantum network, which differs from classical case in that the quantum channels will be consumed if teleportation is performed. We further demonstrated that the expected number of quantum channels represents local correlations depicted by effective circles. Significantly, capacity of quantum communication of quantum networks quantified by ENQC is independent of distance for the communicating nodes, if the effective circles of communication nodes are not overlapped. The expected number of quantum channels can be enhanced through transformations of the lattice configurations of quantum networks via entanglement swapping. Our results can shed lights on the study of quantum communication in quantum networks.

  4. Reliable quantum communication over a quantum relay channel

    Energy Technology Data Exchange (ETDEWEB)

    Gyongyosi, Laszlo, E-mail: gyongyosi@hit.bme.hu [Quantum Technologies Laboratory, Department of Telecommunications, Budapest University of Technology and Economics, 2 Magyar tudosok krt, Budapest, H-1117, Hungary and Information Systems Research Group, Mathematics and Natural Sciences, Hungarian Ac (Hungary); Imre, Sandor [Quantum Technologies Laboratory, Department of Telecommunications, Budapest University of Technology and Economics, 2 Magyar tudosok krt, Budapest, H-1117 (Hungary)

    2014-12-04

    We show that reliable quantum communication over an unreliable quantum relay channels is possible. The coding scheme combines the results on the superadditivity of quantum channels and the efficient quantum coding approaches.

  5. The Forbidden Quantum Adder

    Science.gov (United States)

    Alvarez-Rodriguez, U.; Sanz, M.; Lamata, L.; Solano, E.

    2015-01-01

    Quantum information provides fundamentally different computational resources than classical information. We prove that there is no unitary protocol able to add unknown quantum states belonging to different Hilbert spaces. This is an inherent restriction of quantum physics that is related to the impossibility of copying an arbitrary quantum state, i.e., the no-cloning theorem. Moreover, we demonstrate that a quantum adder, in absence of an ancillary system, is also forbidden for a known orthonormal basis. This allows us to propose an approximate quantum adder that could be implemented in the lab. Finally, we discuss the distinct character of the forbidden quantum adder for quantum states and the allowed quantum adder for density matrices. PMID:26153134

  6. Reliable Quantum Computers

    CERN Document Server

    Preskill, J

    1997-01-01

    The new field of quantum error correction has developed spectacularly since its origin less than two years ago. Encoded quantum information can be protected from errors that arise due to uncontrolled interactions with the environment. Recovery from errors can work effectively even if occasional mistakes occur during the recovery procedure. Furthermore, encoded quantum information can be processed without serious propagation of errors. Hence, an arbitrarily long quantum computation can be performed reliably, provided that the average probability of error per quantum gate is less than a certain critical value, the accuracy threshold. A quantum computer storing about 10^6 qubits, with a probability of error per quantum gate of order 10^{-6}, would be a formidable factoring engine. Even a smaller, less accurate quantum computer would be able to perform many useful tasks. (This paper is based on a talk presented at the ITP Conference on Quantum Coherence and Decoherence, 15-18 December 1996.)

  7. Surprising quantum bounces

    CERN Document Server

    Nesvizhevsky, Valery

    2015-01-01

    This unique book demonstrates the undivided unity and infinite diversity of quantum mechanics using a single phenomenon: quantum bounces of ultra-cold particles. Various examples of such "quantum bounces" are: gravitational quantum states of ultra-cold neutrons (the first observed quantum states of matter in a gravitational field), the neutron whispering gallery (an observed matter-wave analog of the whispering gallery effect well known in acoustics and for electromagnetic waves), and gravitational and whispering gallery states for anti-matter atoms that remain to be observed. These quantum states are an invaluable tool in the search for additional fundamental short-range forces, for exploring the gravitational interaction and quantum effects of gravity, for probing physics beyond the standard model, and for furthering studies into the foundations of quantum mechanics, quantum optics, and surface science.

  8. Quantum data gathering

    Science.gov (United States)

    Blume-Kohout, Robin; Croke, Sarah; Zwolak, Michael

    2013-05-01

    Measurement of a quantum system - the process by which an observer gathers information about it - provides a link between the quantum and classical worlds. The nature of this process is the central issue for attempts to reconcile quantum and classical descriptions of physical processes. Here, we show that the conventional paradigm of quantum measurement is directly responsible for a well-known disparity between the resources required to extract information from quantum and classical systems. We introduce a simple form of quantum data gathering, ``coherent measurement'', that eliminates this disparity and restores a pleasing symmetry between classical and quantum statistical inference. To illustrate the power of quantum data gathering, we demonstrate that coherent measurements are optimal and strictly more powerful than conventional one-at-a-time measurements for the task of discriminating quantum states, including certain entangled many-body states (e.g., matrix product states).

  9. Quantum Hamlet Effect

    CERN Document Server

    Panković, Vladan

    2009-01-01

    In this work, by use of a formalism similar to formalism of the quantum Zeno effect (decrease of the decay probability of an unstable quantum system by frequent measurements) and quantum anti-Zeno effect (increase of the decay probability of an unstable quantum system by frequent measurements), we introduce so-called quantum Hamlet effect. It represents a complete destruction of the quantum predictions on the decay probability of an unstable quantum system by frequent measurement. Precisely, by means of some especial, correctly defined, frequent measurements, decay probability of an unstable quantum system can behave as a divergent series without any definite value. In this way there is quantum mechanically completely unsolvable ``Hamlet dilemma'', to decay or not to decay.

  10. The Forbidden Quantum Adder

    CERN Document Server

    Alvarez-Rodriguez, U; Lamata, L; Solano, E

    2014-01-01

    Addition plays a central role in mathematics and physics, while adders are ubiquitous devices in computation and electronics. In this sense, usual sum operations can be realized by classical Turing machines and also, with a suitable algorithm, by quantum Turing machines. Moreover, the sum of state vectors in the same Hilbert space, known as quantum superposition, is at the core of quantum physics. In fact, entanglement and the promised exponential speed-up of quantum computing are based on such superpositions. Here, we consider the existence of a quantum adder, defined as a unitary operation mapping two unknown quantum states encoded in different quantum systems onto their sum codified in a single one. The surprising answer is that this quantum adder is forbidden and it has the quantum cloning machine as a special case. This no-go result is of fundamental nature and its deep implications should be further studied.

  11. Quantum information and coherence

    CERN Document Server

    Öhberg, Patrik

    2014-01-01

    This book offers an introduction to ten key topics in quantum information science and quantum coherent phenomena, aimed at graduate-student level. The chapters cover some of the most recent developments in this dynamic research field where theoretical and experimental physics, combined with computer science, provide a fascinating arena for groundbreaking new concepts in information processing. The book addresses both the theoretical and experimental aspects of the subject, and clearly demonstrates how progress in experimental techniques has stimulated a great deal of theoretical effort and vice versa. Experiments are shifting from simply preparing and measuring quantum states to controlling and manipulating them, and the book outlines how the first real applications, notably quantum key distribution for secure communication, are starting to emerge. The chapters cover quantum retrodiction, ultracold quantum gases in optical lattices, optomechanics, quantum algorithms, quantum key distribution, quantum cont...

  12. Randomness: quantum versus classical

    CERN Document Server

    Khrennikov, Andrei

    2015-01-01

    Recent tremendous development of quantum information theory led to a number of quantum technological projects, e.g., quantum random generators. This development stimulates a new wave of interest in quantum foundations. One of the most intriguing problems of quantum foundations is elaboration of a consistent and commonly accepted interpretation of quantum state. Closely related problem is clarification of the notion of quantum randomness and its interrelation with classical randomness. In this short review we shall discuss basics of classical theory of randomness (which by itself is very complex and characterized by diversity of approaches) and compare it with irreducible quantum randomness. The second part of this review is devoted to the information interpretation of quantum mechanics (QM) in the spirit of Zeilinger and Brukner (and QBism of Fuchs et al.) and physics in general (e.g., Wheeler's "it from bit") as well as digital philosophy of Chaitin (with historical coupling to ideas of Leibnitz). Finally, w...

  13. Controlling Quantum Information

    CERN Document Server

    Landahl, A J

    2002-01-01

    Quantum information science explores ways in which quantum physical laws can be harnessed to control the acquisition, transmission, protection, and processing of information. This field has seen explosive growth in the past several years from progress on both theoretical and experimental fronts. Essential to this endeavor are methods for controlling quantum information. In this thesis, I present three new approaches for controlling quantum information. First, I present a new protocol for continuously protecting unknown quantum states from noise. This protocol combines and expands ideas from the theories of quantum error correction and quantum feedback control. The result can outperform either approach by itself. I generalize this protocol to all known quantum stabilizer codes, and study its application to the three-qubit repetition code in detail via Monte Carlo simulations. Next, I present several new protocols for controlling quantum information that are fault-tolerant. These protocols require only local qu...

  14. Quantum Junction Solar Cells

    KAUST Repository

    Tang, Jiang

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

  15. Interfacing external quantum devices to a universal quantum computer.

    Science.gov (United States)

    Lagana, Antonio A; Lohe, Max A; von Smekal, Lorenz

    2011-01-01

    We present a scheme to use external quantum devices using the universal quantum computer previously constructed. We thereby show how the universal quantum computer can utilize networked quantum information resources to carry out local computations. Such information may come from specialized quantum devices or even from remote universal quantum computers. We show how to accomplish this by devising universal quantum computer programs that implement well known oracle based quantum algorithms, namely the Deutsch, Deutsch-Jozsa, and the Grover algorithms using external black-box quantum oracle devices. In the process, we demonstrate a method to map existing quantum algorithms onto the universal quantum computer.

  16. Interfacing external quantum devices to a universal quantum computer.

    Directory of Open Access Journals (Sweden)

    Antonio A Lagana

    Full Text Available We present a scheme to use external quantum devices using the universal quantum computer previously constructed. We thereby show how the universal quantum computer can utilize networked quantum information resources to carry out local computations. Such information may come from specialized quantum devices or even from remote universal quantum computers. We show how to accomplish this by devising universal quantum computer programs that implement well known oracle based quantum algorithms, namely the Deutsch, Deutsch-Jozsa, and the Grover algorithms using external black-box quantum oracle devices. In the process, we demonstrate a method to map existing quantum algorithms onto the universal quantum computer.

  17. Scan Quantum Mechanics: Quantum Inertia Stops Superposition

    CERN Document Server

    Gato-Rivera, Beatriz

    2015-01-01

    A novel interpretation of the quantum mechanical superposition is put forward. Quantum systems scan all possible available states and switch randomly and very rapidly among them. The longer they remain in a given state, the larger the probability of the system to be found in that state during a measurement. A crucial property that we postulate is quantum inertia, that increases whenever a constituent is added, or the system is perturbed with all kinds of interactions. Once the quantum inertia $I_q$ reaches a critical value $I_{cr}$ for an observable, the switching among the different eigenvalues of that observable stops and the corresponding superposition comes to an end. Consequently, increasing the mass, temperature, gravitational force, etc. of a quantum system increases its quantum inertia until the superposition of states disappears for all the observables and the system transmutes into a classical one. The process could be reversible decreasing the size, temperature, gravitational force, etc. leading to...

  18. Quantum thermodynamics of general quantum processes.

    Science.gov (United States)

    Binder, Felix; Vinjanampathy, Sai; Modi, Kavan; Goold, John

    2015-03-01

    Accurately describing work extraction from a quantum system is a central objective for the extension of thermodynamics to individual quantum systems. The concepts of work and heat are surprisingly subtle when generalizations are made to arbitrary quantum states. We formulate an operational thermodynamics suitable for application to an open quantum system undergoing quantum evolution under a general quantum process by which we mean a completely positive and trace-preserving map. We derive an operational first law of thermodynamics for such processes and show consistency with the second law. We show that heat, from the first law, is positive when the input state of the map majorizes the output state. Moreover, the change in entropy is also positive for the same majorization condition. This makes a strong connection between the two operational laws of thermodynamics.

  19. Quantum Estimation Methods for Quantum Illumination.

    Science.gov (United States)

    Sanz, M; Las Heras, U; García-Ripoll, J J; Solano, E; Di Candia, R

    2017-02-17

    Quantum illumination consists in shining quantum light on a target region immersed in a bright thermal bath with the aim of detecting the presence of a possible low-reflective object. If the signal is entangled with the receiver, then a suitable choice of the measurement offers a gain with respect to the optimal classical protocol employing coherent states. Here, we tackle this detection problem by using quantum estimation techniques to measure the reflectivity parameter of the object, showing an enhancement in the signal-to-noise ratio up to 3 dB with respect to the classical case when implementing only local measurements. Our approach employs the quantum Fisher information to provide an upper bound for the error probability, supplies the concrete estimator saturating the bound, and extends the quantum illumination protocol to non-Gaussian states. As an example, we show how Schrödinger's cat states may be used for quantum illumination.

  20. Quantum teleportation of propagating quantum microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Di Candia, R.; Felicetti, S.; Sanz, M. [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Fedorov, K.G.; Menzel, E.P. [Bayerische Akademie der Wissenschaften, Walther-Meissner-Institut, Garching (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Zhong, L.; Deppe, F.; Gross, R. [Bayerische Akademie der Wissenschaften, Walther-Meissner-Institut, Garching (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Marx, A. [Bayerische Akademie der Wissenschaften, Walther-Meissner-Institut, Garching (Germany); Solano, E. [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Basque Foundation for Science, IKERBASQUE, Bilbao (Spain)

    2015-12-15

    Propagating quantum microwaves have been proposed and successfully implemented to generate entanglement, thereby establishing a promising platform for the realisation of a quantum communication channel. However, the implementation of quantum teleportation with photons in the microwave regime is still absent. At the same time, recent developments in the field show that this key protocol could be feasible with current technology, which would pave the way to boost the field of microwave quantum communication. Here, we discuss the feasibility of a possible implementation of microwave quantum teleportation in a realistic scenario with losses. Furthermore, we propose how to implement quantum repeaters in the microwave regime without using photodetection, a key prerequisite to achieve long distance entanglement distribution. (orig.)

  1. Quantum revolution

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    The turn of the XXth century witnessed a revolution in physics comparable to Isaac Newton’s discovery of the universal laws of mechanics and of gravitation three centuries earlier. The world required to be described in novel terms, as the immutable, deterministic view of our familiar universe had given way to a new world picture, one which featured chance, flux, and an incessant upsurge of waves of matter. Such a worldview was so radically new and counterintuitive that it gave rise to strong debates, to the effect that Albert Einstein himself tried to oppose it on the grounds that “God does not play dice”. In spite of the intense debates that accompanied its emergence, quantum mechanics quickly proved an incredibly efficacious new tool to understand and to predict a wide array of new phenomena. It was so successful that in no time it broke free from the environment of research labs to become part of daily life, making it possible, for example, to understand why some materials...

  2. Quantum finance

    Science.gov (United States)

    Schaden, Martin

    2002-12-01

    Quantum theory is used to model secondary financial markets. Contrary to stochastic descriptions, the formalism emphasizes the importance of trading in determining the value of a security. All possible realizations of investors holding securities and cash is taken as the basis of the Hilbert space of market states. The temporal evolution of an isolated market is unitary in this space. Linear operators representing basic financial transactions such as cash transfer and the buying or selling of securities are constructed and simple model Hamiltonians that generate the temporal evolution due to cash flows and the trading of securities are proposed. The Hamiltonian describing financial transactions becomes local when the profit/loss from trading is small compared to the turnover. This approximation may describe a highly liquid and efficient stock market. The lognormal probability distribution for the price of a stock with a variance that is proportional to the elapsed time is reproduced for an equilibrium market. The asymptotic volatility of a stock in this case is related to the long-term probability that it is traded.

  3. Quantum information causality.

    Science.gov (United States)

    Pitalúa-García, Damián

    2013-05-24

    How much information can a transmitted physical system fundamentally communicate? We introduce the principle of quantum information causality, which states the maximum amount of quantum information that a quantum system can communicate as a function of its dimension, independently of any previously shared quantum physical resources. We present a new quantum information task, whose success probability is upper bounded by the new principle, and show that an optimal strategy to perform it combines the quantum teleportation and superdense coding protocols with a task that has classical inputs.

  4. Introduction to quantum computers

    CERN Document Server

    Berman, Gennady P; Mainieri, Ronnie; Tsifrinovich, Vladimir I

    1998-01-01

    Quantum computing promises to solve problems which are intractable on digital computers. Highly parallel quantum algorithms can decrease the computational time for some problems by many orders of magnitude. This important book explains how quantum computers can do these amazing things. Several algorithms are illustrated: the discrete Fourier transform, Shor’s algorithm for prime factorization; algorithms for quantum logic gates; physical implementations of quantum logic gates in ion traps and in spin chains; the simplest schemes for quantum error correction; correction of errors caused by im

  5. Physics of quantum rings

    CERN Document Server

    Fomin, Vladimir M

    2013-01-01

    This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is po

  6. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    Semiconductor quantum dots ("solid-state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra. Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dot states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used...

  7. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    1999-01-01

    Semiconductor quantum dots ("solid state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra.Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dots states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used...

  8. Backward Evolving Quantum States

    CERN Document Server

    Vaidman, L

    2006-01-01

    The basic concept of the two-state vector formalism, which is the time symmetric approach to quantum mechanics, is the backward evolving quantum state. However, due to the time asymmetry of the memory's arrow of time, the possible ways to manipulate a backward evolving quantum state differ from those for a standard, forward evolving quantum state. The similarities and the differences between forward and backward evolving quantum states regarding the no-cloning theorem, nonlocal measurements, and teleportation are discussed. The results are relevant not only in the framework of the two-state vector formalism, but also in the framework of retrodictive quantum theory.

  9. Towards a quantum internet

    Science.gov (United States)

    Dür, Wolfgang; Lamprecht, Raphael; Heusler, Stefan

    2017-07-01

    A long-range quantum communication network is among the most promising applications of emerging quantum technologies. We discuss the potential of such a quantum internet for the secure transmission of classical and quantum information, as well as theoretical and experimental approaches and recent advances to realize them. We illustrate the involved concepts such as error correction, teleportation or quantum repeaters and consider an approach to this topic based on catchy visualizations as a context-based, modern treatment of quantum theory at high school.

  10. Counterfactual quantum cryptography.

    Science.gov (United States)

    Noh, Tae-Gon

    2009-12-01

    Quantum cryptography allows one to distribute a secret key between two remote parties using the fundamental principles of quantum mechanics. The well-known established paradigm for the quantum key distribution relies on the actual transmission of signal particle through a quantum channel. In this Letter, we show that the task of a secret key distribution can be accomplished even though a particle carrying secret information is not in fact transmitted through the quantum channel. The proposed protocols can be implemented with current technologies and provide practical security advantages by eliminating the possibility that an eavesdropper can directly access the entire quantum system of each signal particle.

  11. Quantum Contact Transmission

    Institute of Scientific and Technical Information of China (English)

    崔迪

    2015-01-01

    Abstract:Quantum transmission is based on quantum entanglement, which is a kind of the phenomenon of quantum mechanics. Quantum object refers to two or more between the localized, the classic strong correlation. When two object quantum entanglement in the quantum state is not independent, but related, and the correlation distance, a pair of electronic of entanglement state, no matter how far apart, they spin direction will remain an up and a down. If one of the electronic spin direction is changed, another of the electron spin direction wil follow to change immediately.

  12. Principles of quantum chemistry

    CERN Document Server

    George, David V

    2013-01-01

    Principles of Quantum Chemistry focuses on the application of quantum mechanics in physical models and experiments of chemical systems.This book describes chemical bonding and its two specific problems - bonding in complexes and in conjugated organic molecules. The very basic theory of spectroscopy is also considered. Other topics include the early development of quantum theory; particle-in-a-box; general formulation of the theory of quantum mechanics; and treatment of angular momentum in quantum mechanics. The examples of solutions of Schroedinger equations; approximation methods in quantum c

  13. Quantum information. Teleportation - cryptography - quantum computer; Quanteninformation. Teleportation - Kryptografie - Quantencomputer

    Energy Technology Data Exchange (ETDEWEB)

    Koenneker, Carsten (comp.)

    2012-11-01

    The following topics are dealt with: Reality in the test facility, quantum teleportation, the reality of quanta, interaction-free quantum measurement, rules for quantum computers, quantum computers with ions, spintronics with diamond, the limits of the quantum computers, a view in the future of quantum optics. (HSI)

  14. Quantum biology and quantum pharmacology: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Loewdin, P.O.; Oehrn, N.Y.; Sabin, J.R.; Zerner, M.C.

    1986-01-01

    The 25th Sanibel Symposia, which included the 12th meeting of the Symposium on Quantum Biology and Quantum Pharmacology, was held at the University of Florida Whitney Laboratory at Marineland on the Atlantic Coast of Florida, March 14-23, 1985. The three days (March 14-16) devoted to Quantum Biology and Quantum Pharmacology saw the presentation of more than 50 papers by the 90 participants representing about 20 different nations. These ''Proceedings'' comprise the contributions in both the invited talks and the poster sessions.

  15. Quantum dots for quantum information technologies

    CERN Document Server

    2017-01-01

    This book highlights the most recent developments in quantum dot spin physics and the generation of deterministic superior non-classical light states with quantum dots. In particular, it addresses single quantum dot spin manipulation, spin-photon entanglement and the generation of single-photon and entangled photon pair states with nearly ideal properties. The role of semiconductor microcavities, nanophotonic interfaces as well as quantum photonic integrated circuits is emphasized. The latest theoretical and experimental studies of phonon-dressed light matter interaction, single-dot lasing and resonance fluorescence in QD cavity systems are also provided. The book is written by the leading experts in the field.

  16. Aggregating quantum repeaters for the quantum internet

    Science.gov (United States)

    Azuma, Koji; Kato, Go

    2017-09-01

    The quantum internet holds promise for accomplishing quantum teleportation and unconditionally secure communication freely between arbitrary clients all over the globe, as well as the simulation of quantum many-body systems. For such a quantum internet protocol, a general fundamental upper bound on the obtainable entanglement or secret key has been derived [K. Azuma, A. Mizutani, and H.-K. Lo, Nat. Commun. 7, 13523 (2016), 10.1038/ncomms13523]. Here we consider its converse problem. In particular, we present a universal protocol constructible from any given quantum network, which is based on running quantum repeater schemes in parallel over the network. For arbitrary lossy optical channel networks, our protocol has no scaling gap with the upper bound, even based on existing quantum repeater schemes. In an asymptotic limit, our protocol works as an optimal entanglement or secret-key distribution over any quantum network composed of practical channels such as erasure channels, dephasing channels, bosonic quantum amplifier channels, and lossy optical channels.

  17. Quantum paradoxes quantum theory for the perplexed

    CERN Document Server

    Aharonov, Yakir

    2005-01-01

    A Guide through the Mysteries of Quantum Physics!Yakir Aharonov is one of the pioneers in measuring theory, the nature of quantum correlations, superselection rules, and geometric phases and has been awarded numerous scientific honors. The author has contributed monumental concepts to theoretical physics, especially the Aharonov-Bohm effect and the Aharonov-Casher effect. Together with Daniel Rohrlich of the Weizmann Institute, Israel, he has written a pioneering work on the remaining mysteries of quantum mechanics. From the perspective of a preeminent researcher in the fundamental aspects of quantum mechanics, the text combines mathematical rigor with penetrating and concise language

  18. Quantum optics. Gravity meets quantum physics

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Bernhard W. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-02-27

    Albert Einstein’s general theory of relativity is a classical formulation but a quantum mechanical description of gravitational forces is needed, not only to investigate the coupling of classical and quantum systems but simply to give a more complete description of our physical surroundings. In this issue of Nature Photonics, Wen-Te Liao and Sven Ahrens reveal a link between quantum and gravitational physics. They propose that in the quantum-optical effect of superradiance, the world line of electromagnetic radiation is changed by the presence of a gravitational field.

  19. Quantum Darwinism in Quantum Brownian Motion

    Science.gov (United States)

    Blume-Kohout, Robin; Zurek, Wojciech H.

    2008-12-01

    Quantum Darwinism—the redundant encoding of information about a decohering system in its environment—was proposed to reconcile the quantum nature of our Universe with apparent classicality. We report the first study of the dynamics of quantum Darwinism in a realistic model of decoherence, quantum Brownian motion. Prepared in a highly squeezed state—a macroscopic superposition—the system leaves records whose redundancy increases rapidly with initial delocalization. Redundancy appears rapidly (on the decoherence time scale) and persists for a long time.

  20. Quantum neuromorphic hardware for quantum artificial intelligence

    Science.gov (United States)

    Prati, Enrico

    2017-08-01

    The development of machine learning methods based on deep learning boosted the field of artificial intelligence towards unprecedented achievements and application in several fields. Such prominent results were made in parallel with the first successful demonstrations of fault tolerant hardware for quantum information processing. To which extent deep learning can take advantage of the existence of a hardware based on qubits behaving as a universal quantum computer is an open question under investigation. Here I review the convergence between the two fields towards implementation of advanced quantum algorithms, including quantum deep learning.

  1. Converting Coherence to Quantum Correlations.

    Science.gov (United States)

    Ma, Jiajun; Yadin, Benjamin; Girolami, Davide; Vedral, Vlatko; Gu, Mile

    2016-04-22

    Recent results in quantum information theory characterize quantum coherence in the context of resource theories. Here, we study the relation between quantum coherence and quantum discord, a kind of quantum correlation which appears even in nonentangled states. We prove that the creation of quantum discord with multipartite incoherent operations is bounded by the amount of quantum coherence consumed in its subsystems during the process. We show how the interplay between quantum coherence consumption and creation of quantum discord works in the preparation of multipartite quantum correlated states and in the model of deterministic quantum computation with one qubit.

  2. Oplevelsesrige kædebutikker - Sticks'n'Sushi

    DEFF Research Database (Denmark)

    Løkkegaard, Sarai; Pedersen, Kristina Skovgaard

    2014-01-01

    Kædebutikken fremstår som oftest ensartet - til tider grænsende til det kedelige. Konceptuelle retningslinker sikrer kædebutikkens genkendelighed men synes samtidig ødelæggende for dens mulighed for at tilrettelægge unikke og oplevelsesrige udtryk. Men hvordan kan en kædebutik udtrykke ensformige...

  3. Duality quantum computing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this article,we make a review on the development of a newly proposed quantum computer,duality computer,or the duality quantum computer and the duality mode of quantum computers.The duality computer is based on the particle-wave duality principle of quantum mechanics.Compared to an ordinary quantum computer,the duality quantum computer is a quantum computer on the move and passing through a multi-slit.It offers more computing operations than is possible with an ordinary quantum computer.The most two distinct operations are:the quantum division operation and the quantum combiner operation.The division operation divides the wave function of a quantum computer into many attenuated,and identical parts.The combiner operation combines the wave functions in different parts into a single part.The duality mode is a way in which a quantum computer with some extra qubit resource simulates a duality computer.The main structure of duality quantum computer and duality mode,the duality mode,their mathematical description and algorithm designs are reviewed.

  4. Quantum analogue computing.

    Science.gov (United States)

    Kendon, Vivien M; Nemoto, Kae; Munro, William J

    2010-08-13

    We briefly review what a quantum computer is, what it promises to do for us and why it is so hard to build one. Among the first applications anticipated to bear fruit is the quantum simulation of quantum systems. While most quantum computation is an extension of classical digital computation, quantum simulation differs fundamentally in how the data are encoded in the quantum computer. To perform a quantum simulation, the Hilbert space of the system to be simulated is mapped directly onto the Hilbert space of the (logical) qubits in the quantum computer. This type of direct correspondence is how data are encoded in a classical analogue computer. There is no binary encoding, and increasing precision becomes exponentially costly: an extra bit of precision doubles the size of the computer. This has important consequences for both the precision and error-correction requirements of quantum simulation, and significant open questions remain about its practicality. It also means that the quantum version of analogue computers, continuous-variable quantum computers, becomes an equally efficient architecture for quantum simulation. Lessons from past use of classical analogue computers can help us to build better quantum simulators in future.

  5. Quantum Robots and Environments

    CERN Document Server

    Benioff, P

    1998-01-01

    Quantum robots and their interactions with environments of quantum systems are described and their study justified. A quantum robot is a mobile quantum system that includes a quantum computer and needed ancillary systems on board. Quantum robots carry out tasks whose goals include specified changes in the state of the environment or carrying out measurements on the environment. Each task is a sequence of alternating computation and action phases. Computation phase activities include determination of the action to be carried out in the next phase and possible recording of information on neighborhood environmental system states. Action phase activities include motion of the quantum robot and changes of neighborhood environment system states. Models of quantum robots and their interactions with environments are described using discrete space and time. To each task is associated a unitary step operator T that gives the single time step dynamics. T = T_{a}+T_{c} is a sum of action phase and computation phase step ...

  6. Efficient Quantum Pseudorandomness

    Science.gov (United States)

    Brandão, Fernando G. S. L.; Harrow, Aram W.; Horodecki, Michał

    2016-04-01

    Randomness is both a useful way to model natural systems and a useful tool for engineered systems, e.g., in computation, communication, and control. Fully random transformations require exponential time for either classical or quantum systems, but in many cases pseudorandom operations can emulate certain properties of truly random ones. Indeed, in the classical realm there is by now a well-developed theory regarding such pseudorandom operations. However, the construction of such objects turns out to be much harder in the quantum case. Here, we show that random quantum unitary time evolutions ("circuits") are a powerful source of quantum pseudorandomness. This gives for the first time a polynomial-time construction of quantum unitary designs, which can replace fully random operations in most applications, and shows that generic quantum dynamics cannot be distinguished from truly random processes. We discuss applications of our result to quantum information science, cryptography, and understanding the self-equilibration of closed quantum dynamics.

  7. Optical Quantum Computing

    National Research Council Canada - National Science Library

    Jeremy L. O'Brien

    2007-01-01

    In 2001, all-optical quantum computing became feasible with the discovery that scalable quantum computing is possible using only single-photon sources, linear optical elements, and single-photon detectors...

  8. Quantum physics for dummies

    CERN Document Server

    Holzner, Steve

    2013-01-01

    Quantum Physics For Dummies, Revised Edition helps make quantum physics understandable and accessible. From what quantum physics can do for the world to understanding hydrogen atoms, readers will get complete coverage of the subject, along with numerous examples to help them tackle the tough equations. Compatible with classroom text books and courses, Quantum Physics For Dummies, Revised Edition lets students study at their own paces and helps them prepare for graduate or professional exams. Coverage includes: The Schrodinger Equation and its Applications The Foundations of Quantum Physics Vector Notation Spin Scattering Theory, Angular Momentum, and more From the Back Cover Your plain-English guide to understanding and working with the micro world Quantum physics -- also called quantum mechanics or quantum field theory -- can be daunting for even the most dedicated student or enthusiast of science, math, or physics. This friendly, concise guide makes this challenging subject understandable and accessible, fr...

  9. The quantum space race

    Science.gov (United States)

    Jennewein, Thomas; Higgins, Brendon

    2013-03-01

    Sending satellites equipped with quantum technologies into space will be the first step towards a global quantum-communication network. As Thomas Jennewein and Brendon Higgins explain, these systems will also enable physicists to test fundamental physics in new regimes.

  10. Classical and Quantum Polyhedra

    CERN Document Server

    Schliemann, John

    2014-01-01

    Quantum polyhedra constructed from angular momentum operators are the building blocks of space in its quantum description as advocated by Loop Quantum Gravity. Here we extend previous results on the semiclassical properties of quantum polyhedra. Regarding tetrahedra, we compare the results from a canonical quantization of the classical system with a recent wave function based approach to the large-volume sector of the quantum system. Both methods agree in the leading order of the resulting effective operator (given by an harmonic oscillator), while minor differences occur in higher corrections. Perturbative inclusion of such corrections improves the approximation to the eigenstates. Moreover, the comparison of both methods leads also to a full wave function description of the eigenstates of the (square of the) volume operator at negative eigenvalues of large modulus. For the case of general quantum polyhedra described by discrete angular momentum quantum numbers we formulate a set of quantum operators fulfill...

  11. Engineering quantum mechanics

    CERN Document Server

    Ahn, Doyeol

    2011-01-01

    A clear introduction to quantum mechanics concepts Quantum mechanics has become an essential tool for modern engineering, particularly due to the recent developments in quantum computing as well as the rapid progress in optoelectronic devices. Engineering Quantum Mechanics explains the fundamentals of this exciting field, providing broad coverage of both traditional areas such as semiconductor and laser physics as well as relatively new yet fast-growing areas such as quantum computation and quantum information technology. The book begins with basic quantum mechanics, reviewing measurements and probability, Dirac formulation, the uncertainty principle, harmonic oscillator, angular momentum eigenstates, and perturbation theory. Then, quantum statistical mechanics is explored, from second quantization and density operators to coherent and squeezed states, coherent interactions between atoms and fields, and the Jaynes-Cummings model. From there, the book moves into elementary and modern applications, discussing s...

  12. What is Quantum Information?

    Science.gov (United States)

    Lombardi, Olimpia; Fortin, Sebastian; Holik, Federico; López, Cristian

    2017-04-01

    Preface; Introduction; Part I. About the Concept of Information: 1. About the concept of information Sebastian Fortin and Olimpia Lombardi; 2. Representation, information, and theories of information Armond Duwell; 3. Information, communication, and manipulability Olimpia Lombardi and Cristian López; Part II. Information and quantum mechanics: 4. Quantum versus classical information Jeffrey Bub; 5. Quantum information and locality Dennis Dieks; 6. Pragmatic information in quantum mechanics Juan Roederer; 7. Interpretations of quantum theory: a map of madness Adán Cabello; Part III. Probability, Correlations, and Information: 8. On the tension between ontology and epistemology in quantum probabilities Amit Hagar; 9. Inferential versus dynamical conceptions of physics David Wallace; 10. Classical models for quantum information Federico Holik and Gustavo Martin Bosyk; 11. On the relative character of quantum correlations Guido Bellomo and Ángel Ricardo Plastino; Index.

  13. Elements of quantum optics

    CERN Document Server

    Meystre, Pierre

    2007-01-01

    Elements of Quantum Optics gives a self-contained and broad coverage of the basic elements necessary to understand and carry out research in laser physics and quantum optics, including a review of basic quantum mechanics and pedagogical introductions to system-reservoir interactions and to second quantization. The text reveals the close connection between many seemingly unrelated topics, such as probe absorption, four-wave mixing, optical instabilities, resonance fluorescence and squeezing. It also comprises discussions of cavity quantum electrodynamics and atom optics. The 4th edition includes a new chapter on quantum entanglement and quantum information, as well as added discussions of the quantum beam splitter, electromagnetically induced transparency, slow light, and the input-output formalism needed to understand many problems in quantum optics. It also provides an expanded treatment of the minimum-coupling Hamiltonian and a simple derivation of the Gross-Pitaevskii equation, an important gateway to rese...

  14. Quantum Key Distribution

    Science.gov (United States)

    Seshu, Ch.

    Quantum Key Distribution (QKD) uses Quantum Mechanics to guarantee secure communication. It enables two parties to produce a shared random bit string known only to them, which can be used as a key to encrypt and decrypt messages.

  15. Efficient Quantum Pseudorandomness.

    Science.gov (United States)

    Brandão, Fernando G S L; Harrow, Aram W; Horodecki, Michał

    2016-04-29

    Randomness is both a useful way to model natural systems and a useful tool for engineered systems, e.g., in computation, communication, and control. Fully random transformations require exponential time for either classical or quantum systems, but in many cases pseudorandom operations can emulate certain properties of truly random ones. Indeed, in the classical realm there is by now a well-developed theory regarding such pseudorandom operations. However, the construction of such objects turns out to be much harder in the quantum case. Here, we show that random quantum unitary time evolutions ("circuits") are a powerful source of quantum pseudorandomness. This gives for the first time a polynomial-time construction of quantum unitary designs, which can replace fully random operations in most applications, and shows that generic quantum dynamics cannot be distinguished from truly random processes. We discuss applications of our result to quantum information science, cryptography, and understanding the self-equilibration of closed quantum dynamics.

  16. Modeling of quantum nanomechanics

    DEFF Research Database (Denmark)

    Jauho, Antti-Pekka; Novotny, Tomas; Donarini, Andrea

    2004-01-01

    Microelectromechanical systems (MEMS) are approaching the nanoscale, which ultimately implies that the mechanical motion needs to be treated quantum mechanically. In recent years our group has developed theoretical methods to analyze the shuttle transition in the quantum regime (Novotny, 2004...

  17. Joint Quantum Institute

    Data.gov (United States)

    Federal Laboratory Consortium — The Joint Quantum Institute (JQI) is pursuing that goal through the work of leading quantum scientists from the Department of Physics of the University of Maryland...

  18. Quantum Gauge General Relativity

    Institute of Scientific and Technical Information of China (English)

    WU Ning

    2004-01-01

    Based on gauge principle, a new model on quantum gravity is proposed in the frame work of quantum gauge theory of gravity. The model has local gravitational gauge symmetry, and the field equation of the gravitational gauge field is just the famous Einstein's field equation. Because of this reason, this model is called quantum gauge general relativity, which is the consistent unification of quantum theory and general relativity. The model proposed in this paper is a perturbatively renormalizable quantum gravity, which is one of the most important advantage of the quantum gauge general relativity proposed in this paper. Another important advantage of the quantum gauge general relativity is that it can explain both classical tests of gravity and quantum effects of gravitational interactions, such as gravitational phase effects found in COW experiments and gravitational shielding effects found in Podkletnov experiments.

  19. On Universal Quantum Dimensions

    CERN Document Server

    Mkrtchyan, R L

    2016-01-01

    We derive universal expressions for quantum dimensions (universal characters) of some series of irreps of simple Lie algebras. This allows us to check Deligne's hypothesis on universal quantum dimensions for symmetric cube of adjoint representation.

  20. Quantum engineering: Diamond envy

    Science.gov (United States)

    Nunn, Joshua

    2013-03-01

    Nitrogen atoms trapped tens of nanometres apart in diamond can now be linked by quantum entanglement. This ability to produce and control entanglement in solid systems could enable powerful quantum computers.

  1. Quantum Feynman Ratchet

    Science.gov (United States)

    Goyal, Ketan; Kawai, Ryoichi

    As nanotechnology advances, understanding of the thermodynamic properties of small systems becomes increasingly important. Such systems are found throughout physics, biology, and chemistry manifesting striking properties that are a direct result of their small dimensions where fluctuations become predominant. The standard theory of thermodynamics for macroscopic systems is powerless for such ever fluctuating systems. Furthermore, as small systems are inherently quantum mechanical, influence of quantum effects such as discreteness and quantum entanglement on their thermodynamic properties is of great interest. In particular, the quantum fluctuations due to quantum uncertainty principles may play a significant role. In this talk, we investigate thermodynamic properties of an autonomous quantum heat engine, resembling a quantum version of the Feynman Ratchet, in non-equilibrium condition based on the theory of open quantum systems. The heat engine consists of multiple subsystems individually contacted to different thermal environments.

  2. Quantum optics for experimentalists

    CERN Document Server

    Ou, Zhe-Yu Jeff

    2017-01-01

    This book on quantum optics is from the point of view of an experimentalist. It approaches the theory of quantum optics with the language of optical modes of classical wave theory, with which experimentalists are most familiar.

  3. Stochastic processes - quantum physics

    Energy Technology Data Exchange (ETDEWEB)

    Streit, L. (Bielefeld Univ. (Germany, F.R.))

    1984-01-01

    The author presents an elementary introduction to stochastic processes. He starts from simple quantum mechanics and considers problems in probability, finally presenting quantum dynamics in terms of stochastic processes.

  4. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  5. Quantum copying: A review

    Directory of Open Access Journals (Sweden)

    Mark Hillery

    2000-07-01

    Full Text Available Quantum information is stored in two-level quantum systems known as qubits. The no-cloning theorem states that the state of an unknown qubit cannot be copied. This is in contrast to classical information which can be copied. If one drops the requirement that the copies be perfect it is possible to design quantum copiers. This paper presents a short review of the theory of quantum copying.

  6. Reconstructing quantum states efficiently

    OpenAIRE

    Cramer, M; Plenio, M. B.

    2010-01-01

    Quantum state tomography, the ability to deduce the density matrix of a quantum system from measured data, is of fundamental importance for the verification of present and future quantum devices. It has been realized in systems with few components but for larger systems it becomes rapidly infeasible because the number of quantum measurements and computational resources required to process them grow exponentially in the system size. Here we show that we can gain an exponential advantage over d...

  7. Between classical and quantum

    OpenAIRE

    2007-01-01

    The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, including over 500 references. On the assumption that quantum mechanics is universal and complete, we discuss three ways in which classical physics has so far been believed to emerge from quantum physic...

  8. Technology of Quantum Devices

    CERN Document Server

    Razeghi, Manijeh

    2010-01-01

    Technology of Quantum Devices offers a multi-disciplinary overview of solid state physics, photonics and semiconductor growth and fabrication. Readers will find up-to-date coverage of compound semiconductors, crystal growth techniques, silicon and compound semiconductor device technology, in addition to intersubband and semiconductor lasers. Recent findings in quantum tunneling transport, quantum well intersubband photodetectors (QWIP) and quantum dot photodetectors (QWDIP) are described, along with a thorough set of sample problems.

  9. Quantum System Identification

    OpenAIRE

    Burgarth, Daniel; Yuasa, Kazuya

    2011-01-01

    The aim of quantum system identification is to estimate the ingredients inside a black box, in which some quantum-mechanical unitary process takes place, by just looking at its input-output behavior. Here we establish a basic and general framework for quantum system identification, that allows us to classify how much knowledge about the quantum system is attainable, in principle, from a given experimental setup. Prior knowledge on some elements of the black box helps the system identification...

  10. Quantum computing and probability.

    Science.gov (United States)

    Ferry, David K

    2009-11-25

    Over the past two decades, quantum computing has become a popular and promising approach to trying to solve computationally difficult problems. Missing in many descriptions of quantum computing is just how probability enters into the process. Here, we discuss some simple examples of how uncertainty and probability enter, and how this and the ideas of quantum computing challenge our interpretations of quantum mechanics. It is found that this uncertainty can lead to intrinsic decoherence, and this raises challenges for error correction.

  11. Quantum Hamiltonian Complexity

    OpenAIRE

    2014-01-01

    Constraint satisfaction problems are a central pillar of modern computational complexity theory. This survey provides an introduction to the rapidly growing field of Quantum Hamiltonian Complexity, which includes the study of quantum constraint satisfaction problems. Over the past decade and a half, this field has witnessed fundamental breakthroughs, ranging from the establishment of a "Quantum Cook-Levin Theorem" to deep insights into the structure of 1D low-temperature quantum systems via s...

  12. Geometry of Quantum States

    Science.gov (United States)

    Bengtsson, Ingemar; Zyczkowski, Karol

    2007-12-01

    Preface; 1. Convexity, colours and statistics; 2. Geometry of probability distributions; 3. Much ado about spheres; 4. Complex projective spaces; 5. Outline of quantum mechanics; 6. Coherent states and group actions; 7. The stellar representation; 8. The space of density matrices; 9. Purification of mixed quantum states; 10. Quantum operations; 11. Duality: maps versus states; 12. Density matrices and entropies; 13. Distinguishability measures; 14. Monotone metrics and measures; 15. Quantum entanglement; Epilogue; Appendices; References; Index.

  13. Introduction to Quantum Computation

    Science.gov (United States)

    Ekert, A.

    A computation is a physical process. It may be performed by a piece of electronics or on an abacus, or in your brain, but it is a process that takes place in nature and as such it is subject to the laws of physics. Quantum computers are machines that rely on characteristically quantum phenomena, such as quantum interference and quantum entanglement in order to perform computation. In this series of lectures I want to elaborate on the computational power of such machines.

  14. Quantum theory elements

    CERN Document Server

    Bates, David Robert

    1962-01-01

    Quantum Theory: A Treatise in Three Volumes, I: Elements focuses on the principles, methodologies, and approaches involved in quantum theory, including quantum mechanics, linear combinations, collisions, and transitions. The selection first elaborates on the fundamental principles of quantum mechanics, exactly soluble bound state problems, and continuum. Discussions focus on delta function normalization, spherically symmetric potentials, rectangular potential wells, harmonic oscillators, spherically symmetrical potentials, Coulomb potential, axiomatic basis, consequences of first three postula

  15. Testing Nonassociative Quantum Mechanics.

    Science.gov (United States)

    Bojowald, Martin; Brahma, Suddhasattwa; Büyükçam, Umut

    2015-11-27

    The familiar concepts of state vectors and operators in quantum mechanics rely on associative products of observables. However, these notions do not apply to some exotic systems such as magnetic monopoles, which have long been known to lead to nonassociative algebras. Their quantum physics has remained obscure. This Letter presents the first derivation of potentially testable physical results in nonassociative quantum mechanics, based on effective potentials. They imply new effects which cannot be mimicked in usual quantum mechanics with standard magnetic fields.

  16. Quantum walks: a comprehensive review

    CERN Document Server

    Venegas-Andraca, Salvador E

    2012-01-01

    Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important resul...

  17. Multiparty Quantum Secret Sharing of Quantum States with Quantum Registers

    Institute of Scientific and Technical Information of China (English)

    GUO Ying; ZENG Gui-Hua; CHEN Zhi-Gang

    2007-01-01

    A quantum secret sharing scheme is proposed by making use of quantum registers.In the proposed scheme,secret message state is encoded into multipartite entangled states.Several identical multi-particle entanglement states are generated and each particle of the entanglement state is filled in different quantum registers which act as shares of the secret message.Two modes,j.e.the detecting mode and the message mode,are employed so that the eavesdropping can be detected easily and the secret message may be recovered.The seeurity analysis shows that the proposed scheme is secure against eavesdropping of eavesdropper and cheating of participants.

  18. Quantum chaos in quantum Turing machines

    CERN Document Server

    Kim, I; Kim, Ilki; Mahler, Guenter

    1999-01-01

    We investigate a 2-spin quantum Turing architecture, in which discrete local rotations $\\alpha_m$ of the Turing head spin alternate with quantum controlled NOT-opera-\\linebreak%%operations tions. We demonstrate that a single chaotic parameter input $\\alpha_m$ leads to a chaotic dynamics in the entire Hilbert-space.

  19. A Quantum Space behind Simple Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    Chuan Sheng Chew

    2017-01-01

    Full Text Available In physics, experiments ultimately inform us about what constitutes a good theoretical model of any physical concept: physical space should be no exception. The best picture of physical space in Newtonian physics is given by the configuration space of a free particle (or the center of mass of a closed system of particles. This configuration space (as well as phase space can be constructed as a representation space for the relativity symmetry. From the corresponding quantum symmetry, we illustrate the construction of a quantum configuration space, similar to that of quantum phase space, and recover the classical picture as an approximation through a contraction of the (relativity symmetry and its representations. The quantum Hilbert space reduces into a sum of one-dimensional representations for the observable algebra, with the only admissible states given by coherent states and position eigenstates for the phase and configuration space pictures, respectively. This analysis, founded firmly on known physics, provides a quantum picture of physical space beyond that of a finite-dimensional manifold and provides a crucial first link for any theoretical model of quantum space-time at levels beyond simple quantum mechanics. It also suggests looking at quantum physics from a different perspective.

  20. Simulation of quantum computers

    NARCIS (Netherlands)

    De Raedt, H; Michielsen, K; Hams, AH; Miyashita, S; Saito, K; Landau, DP; Lewis, SP; Schuttler, HB

    2001-01-01

    We describe a simulation approach to study the functioning of Quantum Computer hardware. The latter is modeled by a collection of interacting spin-1/2 objects. The time evolution of this spin system maps one-to-one to a quantum program carried out by the Quantum Computer. Our simulation software con

  1. Quantum Boolean image denoising

    Science.gov (United States)

    Mastriani, Mario

    2015-05-01

    A quantum Boolean image processing methodology is presented in this work, with special emphasis in image denoising. A new approach for internal image representation is outlined together with two new interfaces: classical to quantum and quantum to classical. The new quantum Boolean image denoising called quantum Boolean mean filter works with computational basis states (CBS), exclusively. To achieve this, we first decompose the image into its three color components, i.e., red, green and blue. Then, we get the bitplanes for each color, e.g., 8 bits per pixel, i.e., 8 bitplanes per color. From now on, we will work with the bitplane corresponding to the most significant bit (MSB) of each color, exclusive manner. After a classical-to-quantum interface (which includes a classical inverter), we have a quantum Boolean version of the image within the quantum machine. This methodology allows us to avoid the problem of quantum measurement, which alters the results of the measured except in the case of CBS. Said so far is extended to quantum algorithms outside image processing too. After filtering of the inverted version of MSB (inside quantum machine), the result passes through a quantum-classical interface (which involves another classical inverter) and then proceeds to reassemble each color component and finally the ending filtered image. Finally, we discuss the more appropriate metrics for image denoising in a set of experimental results.

  2. Quantum entanglement and symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Chruscinski, D; Kossakowski, A [Institute of Physics, Nicolaus Copernicus University, Grudziadzka 5/7, 87-100 Torun (Poland)

    2007-11-15

    One of the main problem in Quantum Information Theory is to test whether a given state of a composite quantum system is entangled or separable. It turns out that within a class of states invariant under the action of the symmetry group this problem considerably simplifies. We analyze multipartite invariant states and the corresponding symmetric quantum channels.

  3. Quantum entanglement and symmetry

    Science.gov (United States)

    Chruściński, D.; Kossakowski, A.

    2007-11-01

    One of the main problem in Quantum Information Theory is to test whether a given state of a composite quantum system is entangled or separable. It turns out that within a class of states invariant under the action of the symmetry group this problem considerably simplifies. We analyze multipartite invariant states and the corresponding symmetric quantum channels.

  4. Silicon quantum electronics

    NARCIS (Netherlands)

    Zwanenburg, F.A.; Dzurak, A.S.; Morello, A.; Simmons, M.Y.; Hollenberg, L.C.L.; Klimeck, G.; Rogge, S.; Coppersmith, S.N.; Eriksson, M.A.

    2013-01-01

    This review describes recent groundbreaking results in Si, Si/SiGe, and dopant-based quantum dots, and it highlights the remarkable advances in Si-based quantum physics that have occurred in the past few years. This progress has been possible thanks to materials development of Si quantum devices,

  5. Maximally incompatible quantum observables

    Energy Technology Data Exchange (ETDEWEB)

    Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)

    2014-05-01

    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  6. Quantum programming languages

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    After giving a bird's view of some existing quantum programming languages,this paper reports the recent results made by the quantum computation group of the State Key Laboratory for Novel Software Technology and the Department of Computer Science and Technology at Nanjing University,i.e.,the quantum programming languages NDQJava,NDQFP and their processing systems.

  7. Quantum Knitting Computer

    OpenAIRE

    Fujii, Toshiyuki; Matsuo, Shigemasa; Hatakenaka, Noriyuki

    2009-01-01

    We propose a fluxon-controlled quantum computer incorporated with three-qubit quantum error correction using special gate operations, i.e., joint-phase and SWAP gate operations, inherent in capacitively coupled superconducting flux qubits. The proposed quantum computer acts exactly like a knitting machine at home.

  8. Quantum Extended Supersymmetries

    CERN Document Server

    Grigore, D R; Grigore, Dan Radu; Scharf, Gunter

    2003-01-01

    We analyse some quantum multiplets associated with extended supersymmetries. We study in detail the general form of the causal (anti)commutation relations. The condition of positivity of the scalar product imposes severe restrictions on the (quantum) model. It is problematic if one can find out quantum extensions of the standard model with extended supersymmetries.

  9. Quantum secure circuit evaluation

    Institute of Scientific and Technical Information of China (English)

    CHEN Huanhuan; LI Bin; ZHUANG Zhenquan

    2004-01-01

    In order to solve the problem of classical secure circuit evaluation, this paper proposes a quantum approach. In this approach, the method of inserting redundant entangled particles and quantum signature has been employed to strengthen the security of the system. Theoretical analysis shows that our solution is secure against classical and quantum attacks.

  10. Darwinism in quantum systems?

    Science.gov (United States)

    Iqbal, A.; Toor, A. H.

    2002-03-01

    We investigate the role of quantum mechanical effects in the central stability concept of evolutionary game theory, i.e., an evolutionarily stable strategy (ESS). Using two and three-player symmetric quantum games we show how the presence of quantum phenomenon of entanglement can be crucial to decide the course of evolutionary dynamics in a population of interacting individuals.

  11. The Monetary Quantum

    OpenAIRE

    2012-01-01

    The physics of monetary systems works like a systemic quantum process and the monetary quantum moves the economic body of production via mechanic and thermodynamic entropy.This research work compiles the foundations and conclusions of quantum monetary science as new methodical tool for achieving a higher level of economic stability as dynamic efficiency.

  12. Quantum dense key distribution

    CERN Document Server

    Degiovanni, I P; Castelletto, S; Rastello, M L; Bovino, F A; Colla, A M; Castagnoli, G C

    2004-01-01

    This paper proposes a new protocol for quantum dense key distribution. This protocol embeds the benefits of a quantum dense coding and a quantum key distribution and is able to generate shared secret keys four times more efficiently than BB84 one. We hereinafter prove the security of this scheme against individual eavesdropping attacks, and we present preliminary experimental results, showing its feasibility.

  13. Silicon quantum electronics

    NARCIS (Netherlands)

    Zwanenburg, Floris A.; Dzurak, Andrew S.; Morello, Andrea; Simmons, Michelle Y.; Hollenberg, Lloyd C.L.; Klimeck, Gerhard; Rogge, Sven; Coppersmith, Susan N.; Eriksson, Mark A.

    2013-01-01

    This review describes recent groundbreaking results in Si, Si/SiGe , and dopant-based quantum dots, and it highlights the remarkable advances in Si-based quantum physics that have occurred in the past few years. This progress has been possible thanks to materials development of Si quantum devices, a

  14. Introduction to quantum mechanics

    OpenAIRE

    Villaseñor, Eduardo J. S.

    2008-01-01

    The purpose of this contribution is to give a very brief introduction to Quantum Mechanics for an audience of mathematicians. I will follow Segal's approach to Quantum Mechanics paying special attention to algebraic issues. The usual representation of Quantum Mechanics on Hilbert spaces is also discussed.

  15. Silicon Quantum Electronics

    NARCIS (Netherlands)

    Zwanenburg, Floris Arnoud; Dzurak, Andrew S.; Morello, Andrea; Simmons, Michelle Y.; Hollenberg, Lloyd C.L.; Klimeck, Gerhard; Rogge, Sven; Coppersmith, Susan N.; Eriksson, Mark A.

    2013-01-01

    This review describes recent groundbreaking results in Si, Si=SiGe, and dopant-based quantum dots, and it highlights the remarkable advances in Si-based quantum physics that have occurred in the past few years. This progress has been possible thanks to materials development of Si quantum devices,

  16. Quantum Erasure Cryptography

    Science.gov (United States)

    Salih, Hatim

    2016-05-01

    The phenomenon of quantum erasure has long intrigued physicists, but has surprisingly found limited practical application. Here, we propose a protocol for quantum key distribution (QKD) based on quantum erasure, promising inherent security against detector attacks. We particularly demonstrate its security against a powerful detector-blinding attack.

  17. Quantum computing. Defining and detecting quantum speedup.

    Science.gov (United States)

    Rønnow, Troels F; Wang, Zhihui; Job, Joshua; Boixo, Sergio; Isakov, Sergei V; Wecker, David; Martinis, John M; Lidar, Daniel A; Troyer, Matthias

    2014-07-25

    The development of small-scale quantum devices raises the question of how to fairly assess and detect quantum speedup. Here, we show how to define and measure quantum speedup and how to avoid pitfalls that might mask or fake such a speedup. We illustrate our discussion with data from tests run on a D-Wave Two device with up to 503 qubits. By using random spin glass instances as a benchmark, we found no evidence of quantum speedup when the entire data set is considered and obtained inconclusive results when comparing subsets of instances on an instance-by-instance basis. Our results do not rule out the possibility of speedup for other classes of problems and illustrate the subtle nature of the quantum speedup question.

  18. Avoiding Quantum Chaos in Quantum Computation

    CERN Document Server

    Berman, G P; Izrailev, F M; Tsifrinovich, V I

    2001-01-01

    We study a one-dimensional chain of nuclear $1/2-$spins in an external time-dependent magnetic field. This model is considered as a possible candidate for experimental realization of quantum computation. According to the general theory of interacting particles, one of the most dangerous effects is quantum chaos which can destroy the stability of quantum operations. According to the standard viewpoint, the threshold for the onset of quantum chaos due to an interaction between spins (qubits) strongly decreases with an increase of the number of qubits. Contrary to this opinion, we show that the presence of a magnetic field gradient helps to avoid quantum chaos which turns out to disappear with an increase of the number of qubits. We give analytical estimates which explain this effect, together with numerical data supporting

  19. Mesoscopic Cavity Quantum Electrodynamics with Quantum Dots

    CERN Document Server

    Childress, L I; Lukin, M D

    2003-01-01

    We describe an electrodynamic mechanism for coherent, quantum mechanical coupling between spacially separated quantum dots on a microchip. The technique is based on capacitive interactions between the electron charge and a superconducting transmission line resonator, and is closely related to atomic cavity quantum electrodynamics. We investigate several potential applications of this technique which have varying degrees of complexity. In particular, we demonstrate that this mechanism allows design and investigation of an on-chip double-dot microscopic maser. Moreover, the interaction may be extended to couple spatially separated electron spin states while only virtually populating fast-decaying superpositions of charge states. This represents an effective, controllable long-range interaction, which may facilitate implementation of quantum information processing with electron spin qubits and potentially allow coupling to other quantum systems such as atomic or superconducting qubits.

  20. Relativistic quantum chemistry on quantum computers

    DEFF Research Database (Denmark)

    Veis, L.; Visnak, J.; Fleig, T.

    2012-01-01

    The past few years have witnessed a remarkable interest in the application of quantum computing for solving problems in quantum chemistry more efficiently than classical computers allow. Very recently, proof-of-principle experimental realizations have been reported. However, so far only...... the nonrelativistic regime (i.e., the Schrodinger equation) has been explored, while it is well known that relativistic effects can be very important in chemistry. We present a quantum algorithm for relativistic computations of molecular energies. We show how to efficiently solve the eigenproblem of the Dirac......-Coulomb Hamiltonian on a quantum computer and demonstrate the functionality of the proposed procedure by numerical simulations of computations of the spin-orbit splitting in the SbH molecule. Finally, we propose quantum circuits with three qubits and nine or ten controlled-NOT (CNOT) gates, which implement a proof...

  1. The effect of quantum noise on the restricted quantum game

    Institute of Scientific and Technical Information of China (English)

    Cao Shuai; Fang Mao-Fa

    2006-01-01

    It has recently been established that quantum strategies have great advantage over classical ones in quantum games. However, quantum states are easily affected by the quantum noise resulting in decoherence. In this paper, we investigate the effect of quantum noise on the restricted quantum game in which one player is restricted in classical strategic space, another in quantum strategic space and only the quantum player is affected by the quantum noise. Our results show that in the maximally entangled state, no Nash equilibria exist in the range of 0< p≤0.422 (p is the quantum noise parameter), while two special Nash equilibria appear in the range of 0.422 < p< 1. The advantage that the quantum player diminished only in the limit of maximum quantum noise. Increasing the amount of quantum noise leads to the increase of the classical player's payoff and the reduction of the quantum player's payoff, but is helpful in forming two Nash equilibria.

  2. A Study of Quantum Algorithms and Quantum Cryptography

    OpenAIRE

    小柴, 健史

    2007-01-01

    This report describes properties of basic cryptographic primitives (quantum public-key cryptosystmes and quantum one-way functions) in the quantum world where quantum computers are available. Some quantum public-key cryptosystems have already proposed. However, the security requirements for quantum public-key cryptosystems are not studied well. We propose several security notions for quantum public-key cryptosystems and discuss relation among them. In the classical setting, the notion of one-...

  3. Application of Quantum Process Calculus to Higher Dimensional Quantum Protocols

    Directory of Open Access Journals (Sweden)

    Simon J. Gay

    2014-07-01

    Full Text Available We describe the use of quantum process calculus to describe and analyze quantum communication protocols, following the successful field of formal methods from classical computer science. We have extended the quantum process calculus to describe d-dimensional quantum systems, which has not been done before. We summarise the necessary theory in the generalisation of quantum gates and Bell states and use the theory to apply the quantum process calculus CQP to quantum protocols, namely qudit teleportation and superdense coding.

  4. Quantum phase magnification

    Science.gov (United States)

    Hosten, O.; Krishnakumar, R.; Engelsen, N. J.; Kasevich, M. A.

    2016-06-01

    Quantum metrology exploits entangled states of particles to improve sensing precision beyond the limit achievable with uncorrelated particles. All previous methods required detection noise levels below this standard quantum limit to realize the benefits of the intrinsic sensitivity provided by these states. We experimentally demonstrate a widely applicable method for entanglement-enhanced measurements without low-noise detection. The method involves an intermediate quantum phase magnification step that eases implementation complexity. We used it to perform squeezed-state metrology 8 decibels below the standard quantum limit with a detection system that has a noise floor 10 decibels above the standard quantum limit.

  5. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H

    1969-01-01

    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  6. Quantum optics for engineers

    CERN Document Server

    Duarte, FJ

    2013-01-01

    Quantum Optics for Engineers provides a transparent and methodical introduction to quantum optics via the Dirac's bra-ket notation with an emphasis on practical applications and basic aspects of quantum mechanics such as Heisenberg's uncertainty principle and Schrodinger's equation. Self-contained and using mainly first-year calculus and algebra tools, the book:Illustrates the interferometric quantum origin of fundamental optical principles such as diffraction, refraction, and reflectionProvides a transparent introduction, via Dirac's notation, to the probability amplitude of quantum entanglem

  7. Quantum dissipative chaos

    CERN Document Server

    Brun, T A

    1993-01-01

    Using the decoherence formalism of Gell-Mann and Hartle, a quantum system is found which is the equivalent of the classical chaotic Duffing oscillator. The similarities and the differences from the classical oscillator are examined; in particular, a new concept of quantum maps is introduced, and alterations in the classical strange attractor due to the presence of scale- dependent quantum effects are studied. Classical quantities such as the Lyapunov exponents and fractal dimension are examined, and quantum analogs are suggested. These results are generalized into a framework for quantum dissipative chaos, and there is a brief discussion of other work in this area.

  8. Algorithms for Quantum Computers

    CERN Document Server

    Smith, Jamie

    2010-01-01

    This paper surveys the field of quantum computer algorithms. It gives a taste of both the breadth and the depth of the known algorithms for quantum computers, focusing on some of the more recent results. It begins with a brief review of quantum Fourier transform based algorithms, followed by quantum searching and some of its early generalizations. It continues with a more in-depth description of two more recent developments: algorithms developed in the quantum walk paradigm, followed by tensor network evaluation algorithms (which include approximating the Tutte polynomial).

  9. Study of Quantum Computing

    Directory of Open Access Journals (Sweden)

    Prashant Anil Patil

    2012-04-01

    Full Text Available This paper gives the detailed information about Quantum computer, and difference between quantum computer and traditional computers, the basis of Quantum computers which are slightly similar but still different from traditional computer. Many research groups are working towards the highly technological goal of building a quantum computer, which would dramatically improve computational power for particular tasks. Quantum computer is very much use full for computation purpose in field of Science and Research. Large amount of data and information will be computed, processing, storing, retrieving, transmitting and displaying information in less time with that much of accuracy which is not provided by traditional computers.

  10. Quantum machine learning.

    Science.gov (United States)

    Biamonte, Jacob; Wittek, Peter; Pancotti, Nicola; Rebentrost, Patrick; Wiebe, Nathan; Lloyd, Seth

    2017-09-13

    Fuelled by increasing computer power and algorithmic advances, machine learning techniques have become powerful tools for finding patterns in data. Quantum systems produce atypical patterns that classical systems are thought not to produce efficiently, so it is reasonable to postulate that quantum computers may outperform classical computers on machine learning tasks. The field of quantum machine learning explores how to devise and implement quantum software that could enable machine learning that is faster than that of classical computers. Recent work has produced quantum algorithms that could act as the building blocks of machine learning programs, but the hardware and software challenges are still considerable.

  11. Absolutely covert quantum communication

    CERN Document Server

    Bradler, Kamil; Siopsis, George; Weedbrook, Christian

    2016-01-01

    We present truly ultimate limits on covert quantum communication by exploiting quantum-mechanical properties of the Minkowski vacuum in the quantum field theory framework. Our main results are the following: We show how two parties equipped with Unruh-DeWitt detectors can covertly communicate at large distances without the need of hiding in a thermal background or relying on various technological tricks. We reinstate the information-theoretic security standards for reliability of asymptotic quantum communication and show that the rate of covert communication is strictly positive. Therefore, contrary to the previous conclusions, covert and reliable quantum communication is possible.

  12. Principles of quantum electronics

    CERN Document Server

    Marcuse, Dietrich

    1980-01-01

    Principles of Quantum Electronics focuses on the concept of quantum electronics as the application of quantum theory to engineering problems. It examines the principles that govern specific quantum electronics devices and presents their theoretical applications to typical problems. Comprised of 10 chapters, this book starts with an overview of the Dirac formulation of quantum mechanics. This text then considers the derivation of the formalism of field quantization and discusses the properties of photons and phonons. Other chapters examine the interaction between the electromagnetic field and c

  13. Cohering power of quantum operations

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Kaifeng, E-mail: bkf@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China); Kumar, Asutosh, E-mail: asukumar@hri.res.in [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Zhang, Lin, E-mail: linyz@zju.edu.cn [Institute of Mathematics, Hangzhou Dianzi University, Hangzhou 310018 (China); Wu, Junde, E-mail: wjd@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China)

    2017-05-18

    Highlights: • Quantum coherence. • Cohering power: production of quantum coherence by quantum operations. • Study of cohering power and generalized cohering power, and their comparison for differentmeasures of quantum coherence. • Operational interpretation of cohering power. • Bound on cohering power of a generic quantum operation. - Abstract: Quantum coherence and entanglement, which play a crucial role in quantum information processing tasks, are usually fragile under decoherence. Therefore, the production of quantum coherence by quantum operations is important to preserve quantum correlations including entanglement. In this paper, we study cohering power–the ability of quantum operations to produce coherence. First, we provide an operational interpretation of cohering power. Then, we decompose a generic quantum operation into three basic operations, namely, unitary, appending and dismissal operations, and show that the cohering power of any quantum operation is upper bounded by the corresponding unitary operation. Furthermore, we compare cohering power and generalized cohering power of quantum operations for different measures of coherence.

  14. Two quantum Simpson's paradoxes

    CERN Document Server

    Paris, Matteo G A

    2012-01-01

    The so-called Simpson's "paradox", or Yule-Simpson (YS) effect, occurs in classical statistics when the correlations that are present among different sets of samples are reversed if the sets are combined together, thus ignoring one or more lurking variables. Here we illustrate the occurrence of two analogue effects in quantum measurements. The first, which we term quantum-classical YS effect, may occur with quantum limited measurements and with lurking variables coming from the mixing of states, whereas the second, here referred to as quantum-quantum YS effect, may take place when coherent superpositions of quantum states are allowed. By analyzing quantum measurements on low dimensional systems (qubits and qutrits), we show that the two effects may occur independently, and that the quantum-quantum YS effect is more likely to occur than the corresponding quantum-classical one. We also found that there exist classes of superposition states for which the quantum-classical YS effect cannot occur for any measureme...

  15. Quantum robots plus environments.

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.

    1998-07-23

    A quantum robot is a mobile quantum system, including an on board quantum computer and needed ancillary systems, that interacts with an environment of quantum systems. Quantum robots carry out tasks whose goals include making specified changes in the state of the environment or carrying out measurements on the environment. The environments considered so far, oracles, data bases, and quantum registers, are seen to be special cases of environments considered here. It is also seen that a quantum robot should include a quantum computer and cannot be simply a multistate head. A model of quantum robots and their interactions is discussed in which each task, as a sequence of alternating computation and action phases,is described by a unitary single time step operator T {approx} T{sub a} + T{sub c} (discrete space and time are assumed). The overall system dynamics is described as a sum over paths of completed computation (T{sub c}) and action (T{sub a}) phases. A simple example of a task, measuring the distance between the quantum robot and a particle on a 1D lattice with quantum phase path dispersion present, is analyzed. A decision diagram for the task is presented and analyzed.

  16. Physics of quantum rings

    Energy Technology Data Exchange (ETDEWEB)

    Fomin, Vladimir M. (ed.) [Leibniz Institute for Solid State and Materials Research, Dresden (Germany)

    2014-07-01

    Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

  17. Quantum Kolmogorov Complexity

    CERN Document Server

    Berthiaume, A; Laplante, S; Berthiaume, Andre; Dam, Wim van; Laplante, Sophie

    2000-01-01

    In this paper we give a definition for quantum Kolmogorov complexity. In the classical setting, the Kolmogorov complexity of a string is the length of the shortest program that can produce this string as its output. It is a measure of the amount of innate randomness (or information) contained in the string. We define the quantum Kolmogorov complexity of a qubit string as the length of the shortest quantum input to a universal quantum Turing machine that produces the initial qubit string with high fidelity. The definition of Vitanyi (Proceedings of the 15th IEEE Annual Conference on Computational Complexity, 2000) measures the amount of classical information, whereas we consider the amount of quantum information in a qubit string. We argue that our definition is natural and is an accurate representation of the amount of quantum information contained in a quantum state.

  18. Advanced Visual Quantum Mechanics

    CERN Document Server

    Thaller, Bernd

    2005-01-01

    Advanced Visual Quantum Mechanics is a systematic effort to investigate and to teach quantum mechanics with the aid of computer-generated animations. It is a self-contained textbook that combines selected topics from atomic physics (spherical symmetry, the hydrogen atom, and particles with spin) with an introduction to quantum information theory (qubits, EPR paradox, teleportation, quantum computers). It explores relativistic quantum mechanics and the strange behavior of Dirac equation solutions. A series of appendices covers important topics from perturbation and scattering theory. The book places an emphasis on ideas and concepts, with a fair to moderate amount of mathematical rigor. Though this book stands alone, it can also be paired with Thaller Visual Quantum Mechanics to form a comprehensive course in quantum mechanics. The software for the first book earned the European Academic Software Award 2000 for outstanding innovation in its field.

  19. Sorting quantum systems efficiently

    Science.gov (United States)

    Ionicioiu, Radu

    2016-05-01

    Measuring the state of a quantum system is a fundamental process in quantum mechanics and plays an essential role in quantum information and quantum technologies. One method to measure a quantum observable is to sort the system in different spatial modes according to the measured value, followed by single-particle detectors on each mode. Examples of quantum sorters are polarizing beam-splitters (PBS) – which direct photons according to their polarization – and Stern-Gerlach devices. Here we propose a general scheme to sort a quantum system according to the value of any d-dimensional degree of freedom, such as spin, orbital angular momentum (OAM), wavelength etc. Our scheme is universal, works at the single-particle level and has a theoretical efficiency of 100%. As an application we design an efficient OAM sorter consisting of a single multi-path interferometer which is suitable for a photonic chip implementation.

  20. Universal quantum sorter

    CERN Document Server

    Ionicioiu, Radu

    2015-01-01

    Measuring the state of a quantum system is a fundamental process in quantum mechanics and plays an essential role in quantum information and quantum technologies. One method to measure a quantum observable is to sort the system in different spatial modes according to the measured value, followed by single-particle detectors on each mode. Examples of quantum sorters are polarizing beam-splitters (PBS) -- which direct photons according to their polarization -- and Stern-Gerlach devices. Here we propose a general scheme to sort a quantum system according to the value of any $d$-dimensional degree of freedom, such as spin, orbital angular momentum (OAM), wavelength etc. Our scheme is universal, works at single-particle level and has a theoretical efficiency of 100%. As an application we design an efficient OAM sorter consisting of a single multi-path interferometer which is suitable for a photonic chip implementation.

  1. Quantum Soliton Evaporation

    CERN Document Server

    Villari, Leone Di Mauro; Biancalana, Fabio; Conti, Claudio

    2016-01-01

    We have very little experience of the quantum dynamics of the ubiquitous nonlinear waves. Observed phenomena in high energy physics are perturbations to linear waves, and classical nonlinear waves, like solitons, are barely affected by quantum effects. We know that solitons, immutable in classical physics, exhibit collapse and revivals according to quantum mechanics. However this effect is very weak and has never been observed experimentally. By predicting black hole evaporation Hawking first introduced a distinctly quantum effect in nonlinear gravitational physics.Here we show the existence of a general and universal quantum process whereby a soliton emits quantum radiation with a specific frequency content, and a temperature given by the number of quanta, the soliton Schwarzschild radius, and the amount of nonlinearity, in a precise and surprisingly simple way. This result may ultimately lead to the first experimental evidence of genuine quantum black hole evaporation. In addition, our results show that bla...

  2. Quantum Social Science

    Science.gov (United States)

    Haven, Emmanuel; Khrennikov, Andrei

    2013-01-01

    Preface; Part I. Physics Concepts in Social Science? A Discussion: 1. Classical, statistical and quantum mechanics: all in one; 2. Econophysics: statistical physics and social science; 3. Quantum social science: a non-mathematical motivation; Part II. Mathematics and Physics Preliminaries: 4. Vector calculus and other mathematical preliminaries; 5. Basic elements of quantum mechanics; 6. Basic elements of Bohmian mechanics; Part III. Quantum Probabilistic Effects in Psychology: Basic Questions and Answers: 7. A brief overview; 8. Interference effects in psychology - an introduction; 9. A quantum-like model of decision making; Part IV. Other Quantum Probabilistic Effects in Economics, Finance and Brain Sciences: 10. Financial/economic theory in crisis; 11. Bohmian mechanics in finance and economics; 12. The Bohm-Vigier Model and path simulation; 13. Other applications to economic/financial theory; 14. The neurophysiological sources of quantum-like processing in the brain; Conclusion; Glossary; Index.

  3. Quantum-limit spectroscopy

    CERN Document Server

    Ficek, Zbigniew

    2017-01-01

    This book covers the main ideas, methods, and recent developments of quantum-limit optical spectroscopy and applications to quantum information, resolution spectroscopy, measurements beyond quantum limits, measurement of decoherence, and entanglement. Quantum-limit spectroscopy lies at the frontier of current experimental and theoretical techniques, and is one of the areas of atomic spectroscopy where the quantization of the field is essential to predict and interpret the existing experimental results. Currently, there is an increasing interest in quantum and precision spectroscopy both theoretically and experimentally, due to significant progress in trapping and cooling of single atoms and ions. This progress allows one to explore in the most intimate detail the ways in which light interacts with atoms and to measure spectral properties and quantum effects with high precision. Moreover, it allows one to perform subtle tests of quantum mechanics on the single atom and single photon scale which were hardly eve...

  4. Quantum broadcast channels

    CERN Document Server

    Yard, J; Devetak, I; Yard, Jon; Hayden, Patrick; Devetak, Igor

    2006-01-01

    We analyze quantum broadcast channels, which are quantum channels with a single sender and many receivers. Focusing on channels with two receivers for simplicity, we generalize a number of results from the network Shannon theory literature which give the rates at which two senders can receive a common message, while a personalized one is sent to one of them. Our first collection of results applies to channels with a classical input and quantum outputs. The second class of theorems we prove concern sending a common classical message over a quantum broadcast channel, while sending quantum information to one of the receivers. The third group of results we obtain concern communication over an isometry, giving the rates at quantum information can be sent to one receiver, while common quantum information is sent to both, in the sense that tripartite GHZ entanglement is established. For each scenario, we provide an additivity proof for an appropriate class of channels, yielding single-letter characterizations of the...

  5. Quantum social science

    CERN Document Server

    Haven, Emmanuel

    2013-01-01

    Written by world experts in the foundations of quantum mechanics and its applications to social science, this book shows how elementary quantum mechanical principles can be applied to decision-making paradoxes in psychology and used in modelling information in finance and economics. The book starts with a thorough overview of some of the salient differences between classical, statistical and quantum mechanics. It presents arguments on why quantum mechanics can be applied outside of physics and defines quantum social science. The issue of the existence of quantum probabilistic effects in psychology, economics and finance is addressed and basic questions and answers are provided. Aimed at researchers in economics and psychology, as well as physics, basic mathematical preliminaries and elementary concepts from quantum mechanics are defined in a self-contained way.

  6. What is quantum information ?

    CERN Document Server

    Fortin, Sebastian; Holik, Federico; López, Cristian

    2017-01-01

    Combining physics and philosophy, this is a uniquely interdisciplinary examination of quantum information science which provides an up-to-date examination of developments in this field. The authors provide coherent definitions and theories of information, taking clearly defined approaches to considering information in connection with quantum mechanics, probability, and correlations. Concepts addressed include entanglement of quantum states, the relation of quantum correlations to quantum information, and the meaning of the informational approach for the foundations of quantum mechanics. Furthermore, the mathematical concept of information in the communicational context, and the notion of pragmatic information are considered. Suitable as both a discussion of the conceptual and philosophical problems of this field and a comprehensive stand-alone introduction, this book will benefit both experienced and new researchers in quantum information and the philosophy of physics.

  7. Quantum Pseudo-Telepathy

    CERN Document Server

    Brassard, G; Tapp, A; Brassard, Gilles; Broadbent, Anne; Tapp, Alain

    2004-01-01

    Quantum information processing is at the crossroads of physics, mathematics and computer science. It is concerned with that we can and cannot do with quantum information that goes beyond the abilities of classical information processing devices. Communication complexity is an area of classical computer science that aims at quantifying the amount of communication necessary to solve distributed computational problems. Quantum communication complexity uses quantum mechanics to reduce the amount of communication that would be classically required. Pseudo-telepathy is a surprising application of quantum information processing to communication complexity. Thanks to entanglement, perhaps the most nonclassical manifestation of quantum mechanics, two or more quantum players can accomplish a distributed task with no need for communication whatsoever, which would be an impossible feat for classical players. After a detailed overview of the principle and purpose of pseudo-telepathy, we present a survey of recent and no-s...

  8. Quantum random number generators

    Science.gov (United States)

    Herrero-Collantes, Miguel; Garcia-Escartin, Juan Carlos

    2017-01-01

    Random numbers are a fundamental resource in science and engineering with important applications in simulation and cryptography. The inherent randomness at the core of quantum mechanics makes quantum systems a perfect source of entropy. Quantum random number generation is one of the most mature quantum technologies with many alternative generation methods. This review discusses the different technologies in quantum random number generation from the early devices based on radioactive decay to the multiple ways to use the quantum states of light to gather entropy from a quantum origin. Randomness extraction and amplification and the notable possibility of generating trusted random numbers even with untrusted hardware using device-independent generation protocols are also discussed.

  9. Quantum simulation of a quantum stochastic walk

    Science.gov (United States)

    Govia, Luke C. G.; Taketani, Bruno G.; Schuhmacher, Peter K.; Wilhelm, Frank K.

    2017-03-01

    The study of quantum walks has been shown to have a wide range of applications in areas such as artificial intelligence, the study of biological processes, and quantum transport. The quantum stochastic walk (QSW), which allows for incoherent movement of the walker, and therefore, directionality, is a generalization on the fully coherent quantum walk. While a QSW can always be described in Lindblad formalism, this does not mean that it can be microscopically derived in the standard weak-coupling limit under the Born–Markov approximation. This restricts the class of QSWs that can be experimentally realized in a simple manner. To circumvent this restriction, we introduce a technique to simulate open system evolution on a fully coherent quantum computer, using a quantum trajectories style approach. We apply this technique to a broad class of QSWs, and show that they can be simulated with minimal experimental resources. Our work opens the path towards the experimental realization of QSWs on large graphs with existing quantum technologies.

  10. Quantum Computer Using Coupled Quantum Dot Molecules

    CERN Document Server

    Wu, N J; Natori, A; Yasunaga, H; Wu*, Nan-Jian

    1999-01-01

    We propose a method for implementation of a quantum computer using artificial molecules. The artificial molecule consists of two coupled quantum dots stacked along z direction and one single electron. One-qubit and two-qubit gates are constructed by one molecule and two coupled molecules, respectively.The ground state and the first excited state of the molecule are used to encode the |0> and |1> states of a qubit. The qubit is manipulated by a resonant electromagnetic wave that is applied directly to the qubit through a microstrip line. The coupling between two qubits in a quantum controlled NOT gate is switched on (off) by floating (grounding) the metal film electrodes. We study the operations of the gates by using a box-shaped quantum dot model and numerically solving a time-dependent Schridinger equation, and demonstrate that the quantum gates can perform the quantum computation. The operating speed of the gates is about one operation per 4ps. The reading operation of the output of the quantum computer can...

  11. Introduction to quantum information science

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Masahito [Nagoya Univ. (Japan). Graduate School of Mathematics; Ishizaka, Satoshi [Hiroshima Univ., Higashi-Hiroshima (Japan). Graduate School of Integrated Arts and Sciences; Kawachi, Akinori [Tokyo Institute of Technology (Japan). Dept. of Mathematical and Computing Sciences; Kimura, Gen [Shibaura Institute of Technology, Saitama (Japan). College of Systems Engineering and Science; Ogawa, Tomohiro [Univ. of Electro-Communications, Tokyo (Japan). Graduate School of Information Systems

    2015-04-01

    Presents the mathematical foundation for quantum information in a very didactic way. Summarizes all required mathematical knowledge in linear algebra. Supports teaching and learning with more than 100 exercises with solutions. Includes brief descriptions to recent results with references. This book presents the basics of quantum information, e.g., foundation of quantum theory, quantum algorithms, quantum entanglement, quantum entropies, quantum coding, quantum error correction and quantum cryptography. The required knowledge is only elementary calculus and linear algebra. This way the book can be understood by undergraduate students. In order to study quantum information, one usually has to study the foundation of quantum theory. This book describes it from more an operational viewpoint which is suitable for quantum information while traditional textbooks of quantum theory lack this viewpoint. The current book bases on Shor's algorithm, Grover's algorithm, Deutsch-Jozsa's algorithm as basic algorithms. To treat several topics in quantum information, this book covers several kinds of information quantities in quantum systems including von Neumann entropy. The limits of several kinds of quantum information processing are given. As important quantum protocols,this book contains quantum teleportation, quantum dense coding, quantum data compression. In particular conversion theory of entanglement via local operation and classical communication are treated too. This theory provides the quantification of entanglement, which coincides with von Neumann entropy. The next part treats the quantum hypothesis testing. The decision problem of two candidates of the unknown state are given. The asymptotic performance of this problem is characterized by information quantities. Using this result, the optimal performance of classical information transmission via noisy quantum channel is derived. Quantum information transmission via noisy quantum channel by quantum error

  12. Multiphoton quantum optics and quantum state engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dell' Anno, Fabio [Dipartimento di Fisica ' E. R. Caianiello' , Universita degli Studi di Salerno, CNISM and CNR-INFM Coherentia, and INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, I-84081 Baronissi (Saudi Arabia) (Italy)]. E-mail: dellanno@sa.infn.it; De Siena, Silvio [Dipartimento di Fisica ' E. R. Caianiello' , Universita degli Studi di Salerno, CNISM and CNR-INFM Coherentia, and INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, I-84081 Baronissi (SA) (Italy)]. E-mail: desiena@sa.infn.it; Illuminati, Fabrizio [Dipartimento di Fisica ' E. R. Caianiello' , Universita degli Studi di Salerno, CNISM and CNR-INFM Coherentia, and INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, I-84081 Baronissi (SA) (Italy)]. E-mail: illuminati@sa.infn.it

    2006-05-15

    We present a review of theoretical and experimental aspects of multiphoton quantum optics. Multiphoton processes occur and are important for many aspects of matter-radiation interactions that include the efficient ionization of atoms and molecules, and, more generally, atomic transition mechanisms; system-environment couplings and dissipative quantum dynamics; laser physics, optical parametric processes, and interferometry. A single review cannot account for all aspects of such an enormously vast subject. Here we choose to concentrate our attention on parametric processes in nonlinear media, with special emphasis on the engineering of nonclassical states of photons and atoms that are relevant for the conceptual investigations as well as for the practical applications of forefront aspects of modern quantum mechanics. We present a detailed analysis of the methods and techniques for the production of genuinely quantum multiphoton processes in nonlinear media, and the corresponding models of multiphoton effective interactions. We review existing proposals for the classification, engineering, and manipulation of nonclassical states, including Fock states, macroscopic superposition states, and multiphoton generalized coherent states. We introduce and discuss the structure of canonical multiphoton quantum optics and the associated one- and two-mode canonical multiphoton squeezed states. This framework provides a consistent multiphoton generalization of two-photon quantum optics and a consistent Hamiltonian description of multiphoton processes associated to higher-order nonlinearities. Finally, we discuss very recent advances that by combining linear and nonlinear optical devices allow to realize multiphoton entangled states of the electromagnetic field, either in discrete or in continuous variables, that are relevant for applications to efficient quantum computation, quantum teleportation, and related problems in quantum communication and information.

  13. Quantum Discord for Investigating Quantum Correlations without Entanglement in Solids

    CERN Document Server

    Rong, Xing; Jin, Fangzhou; Geng, Jianpei; Feng, Pengbo; Xu, Nanyang; Wang, Ya; Ju, Chenyong; Shi, Mingjun; Du, Jiangfeng

    2012-01-01

    Quantum systems unfold diversified correlations which have no classical counterparts. These quantum correlations have various different facets. Quantum entanglement, as the most well known measure of quantum correlations, plays essential roles in quantum information processing. However, it has recently been pointed out that quantum entanglement cannot describe all the nonclassicality in the correlations. Thus the study of quantum correlations in separable states attracts widely attentions. Herein, we experimentally investigate the quantum correlations of separable thermal states in terms of quantum discord. The sudden change of quantum discord is observed, which captures ambiguously the critical point associated with the behavior of Hamiltonian. Our results display the potential applications of quantum correlations in studying the fundamental properties of quantum system, such as quantum criticality of non-zero temperature.

  14. Approximate Quantum Adders with Genetic Algorithms: An IBM Quantum Experience

    Directory of Open Access Journals (Sweden)

    Li Rui

    2017-07-01

    Full Text Available It has been proven that quantum adders are forbidden by the laws of quantum mechanics. We analyze theoretical proposals for the implementation of approximate quantum adders and optimize them by means of genetic algorithms, improving previous protocols in terms of efficiency and fidelity. Furthermore, we experimentally realize a suitable approximate quantum adder with the cloud quantum computing facilities provided by IBM Quantum Experience. The development of approximate quantum adders enhances the toolbox of quantum information protocols, paving the way for novel applications in quantum technologies.

  15. Approximate Quantum Adders with Genetic Algorithms: An IBM Quantum Experience

    Science.gov (United States)

    Li, Rui; Alvarez-Rodriguez, Unai; Lamata, Lucas; Solano, Enrique

    2017-07-01

    It has been proven that quantum adders are forbidden by the laws of quantum mechanics. We analyze theoretical proposals for the implementation of approximate quantum adders and optimize them by means of genetic algorithms, improving previous protocols in terms of efficiency and fidelity. Furthermore, we experimentally realize a suitable approximate quantum adder with the cloud quantum computing facilities provided by IBM Quantum Experience. The development of approximate quantum adders enhances the toolbox of quantum information protocols, paving the way for novel applications in quantum technologies.

  16. Quantum entanglement and quantum computational algorithms

    Indian Academy of Sciences (India)

    Arvind

    2001-02-01

    The existence of entangled quantum states gives extra power to quantum computers over their classical counterparts. Quantum entanglement shows up qualitatively at the level of two qubits. We demonstrate that the one- and the two-bit Deutsch-Jozsa algorithm does not require entanglement and can be mapped onto a classical optical scheme. It is only for three and more input bits that the DJ algorithm requires the implementation of entangling transformations and in these cases it is impossible to implement this algorithm classically

  17. Quantum gravitational contributions to quantum electrodynamics.

    Science.gov (United States)

    Toms, David J

    2010-11-01

    Quantum electrodynamics describes the interactions of electrons and photons. Electric charge (the gauge coupling constant) is energy dependent, and there is a previous claim that charge is affected by gravity (described by general relativity) with the implication that the charge is reduced at high energies. However, that claim has been very controversial and the matter has not been settled. Here I report an analysis (free from the earlier controversies) demonstrating that quantum gravity corrections to quantum electrodynamics have a quadratic energy dependence that result in the electric charge vanishing at high energies, a result known as asymptotic freedom.

  18. Quantum information: primitive notions and quantum correlations

    CERN Document Server

    Scarani, Valerio

    2009-01-01

    This series of introductory lectures consists of two parts. In the first part, I rapidly review the basic notions of quantum physics and many primitives of quantum information (i.e. notions that one must be somehow familiar with in the field, like cloning, teleportation, state estimation...). The second part is devoted to a detailed introduction to the topic of quantum correlations, covering the evidence for failure of alternative theories, some aspects of the formalism of no-signaling probability distributions and some hints towards some current research topics in the field.

  19. Using a quantum computer to investigate quantum chaos

    OpenAIRE

    Schack, Ruediger

    1997-01-01

    We show that the quantum baker's map, a prototypical map invented for theoretical studies of quantum chaos, has a very simple realization in terms of quantum gates. Chaos in the quantum baker's map could be investigated experimentally on a quantum computer based on only 3 qubits.

  20. Linear optics implementation for quantum game under quantum noise

    Institute of Scientific and Technical Information of China (English)

    Cao Shuai; Fang Mao-Fa

    2006-01-01

    It has recently been shown that linear optics alone would suffice to implement efficient quantum computation. Quantum computation circuits using coherent states as the logical qubits can be constructed from very simple linear networks, conditional measurements and coherent superposition resource states. We present the quantum game under quantum noise and a proposal for implementing the noisy quantum game using only linear optics.

  1. Quantum information theory mathematical foundation

    CERN Document Server

    Hayashi, Masahito

    2017-01-01

    This graduate textbook provides a unified view of quantum information theory. Clearly explaining the necessary mathematical basis, it merges key topics from both information-theoretic and quantum- mechanical viewpoints and provides lucid explanations of the basic results. Thanks to this unified approach, it makes accessible such advanced topics in quantum communication as quantum teleportation, superdense coding, quantum state transmission (quantum error-correction) and quantum encryption. Since the publication of the preceding book Quantum Information: An Introduction, there have been tremendous strides in the field of quantum information. In particular, the following topics – all of which are addressed here – made seen major advances: quantum state discrimination, quantum channel capacity, bipartite and multipartite entanglement, security analysis on quantum communication, reverse Shannon theorem and uncertainty relation. With regard to the analysis of quantum security, the present book employs an impro...

  2. Quantum Computational Cryptography

    Science.gov (United States)

    Kawachi, Akinori; Koshiba, Takeshi

    As computational approaches to classical cryptography have succeeded in the establishment of the foundation of the network security, computational approaches even to quantum cryptography are promising, since quantum computational cryptography could offer richer applications than the quantum key distribution. Our project focused especially on the quantum one-wayness and quantum public-key cryptosystems. The one-wayness of functions (or permutations) is one of the most important notions in computational cryptography. First, we give an algorithmic characterization of quantum one-way permutations. In other words, we show a necessary and sufficient condition for quantum one-way permutations in terms of reflection operators. Second, we introduce a problem of distinguishing between two quantum states as a new underlying problem that is harder to solve than the graph automorphism problem. The new problem is a natural generalization of the distinguishability problem between two probability distributions, which are commonly used in computational cryptography. We show that the problem has several cryptographic properties and they enable us to construct a quantum publickey cryptosystem, which is likely to withstand any attack of a quantum adversary.

  3. Quantum secret sharing with minimized quantum communication

    Science.gov (United States)

    Fortescue, Ben; Gour, Gilad

    2013-03-01

    Standard techniques for sharing a quantum secret among multiple players (such that certain subsets of the players can recover the secret while others are denied all knowledge of the secret) require a large amount of quantum communication to distribute the secret, which is likely to be the most costly resource in any practical scheme. Two known methods for reducing this cost are the use of imperfect ``ramp'' secret sharing (in which security is sacrificed for efficiency) and classical encryption (in which certain elements of the players' shares consist of classical information only). We demonstrate how one may combine these methods to reduce the required quantum communication below what has been previously achieved, in some cases to a provable minimum, without any loss of security. The techniques involved are closely-related to the properties of stabilizer codes, and thus have strong potential for being adapted to a wide range of quantum secret sharing schemes.

  4. Towards quantum chemistry on a quantum computer.

    Science.gov (United States)

    Lanyon, B P; Whitfield, J D; Gillett, G G; Goggin, M E; Almeida, M P; Kassal, I; Biamonte, J D; Mohseni, M; Powell, B J; Barbieri, M; Aspuru-Guzik, A; White, A G

    2010-02-01

    Exact first-principles calculations of molecular properties are currently intractable because their computational cost grows exponentially with both the number of atoms and basis set size. A solution is to move to a radically different model of computing by building a quantum computer, which is a device that uses quantum systems themselves to store and process data. Here we report the application of the latest photonic quantum computer technology to calculate properties of the smallest molecular system: the hydrogen molecule in a minimal basis. We calculate the complete energy spectrum to 20 bits of precision and discuss how the technique can be expanded to solve large-scale chemical problems that lie beyond the reach of modern supercomputers. These results represent an early practical step toward a powerful tool with a broad range of quantum-chemical applications.

  5. Quantum information theory and quantum statistics

    Energy Technology Data Exchange (ETDEWEB)

    Petz, D. [Alfred Renyi Institute of Mathematics, Budapest (Hungary)

    2008-07-01

    Based on lectures given by the author, this book focuses on providing reliable introductory explanations of key concepts of quantum information theory and quantum statistics - rather than on results. The mathematically rigorous presentation is supported by numerous examples and exercises and by an appendix summarizing the relevant aspects of linear analysis. Assuming that the reader is familiar with the content of standard undergraduate courses in quantum mechanics, probability theory, linear algebra and functional analysis, the book addresses graduate students of mathematics and physics as well as theoretical and mathematical physicists. Conceived as a primer to bridge the gap between statistical physics and quantum information, a field to which the author has contributed significantly himself, it emphasizes concepts and thorough discussions of the fundamental notions to prepare the reader for deeper studies, not least through the selection of well chosen exercises. (orig.)

  6. Noncommutative Quantum Mechanics and Quantum Cosmology

    CERN Document Server

    Bastos, Catarina; Dias, Nuno; Prata, Joao Nuno

    2009-01-01

    We present a phase-space noncommutative version of quantum mechanics and apply this extension to Quantum Cosmology. We motivate this type of noncommutative algebra through the gravitational quantum well (GQW) where the noncommutativity between momenta is shown to be relevant. We also discuss some qualitative features of the GQW such as the Berry phase. In the context of quantum cosmology we consider a Kantowski-Sachs cosmological model and obtain the Wheeler-DeWitt (WDW) equation for the noncommutative system through the ADM formalism and a suitable Seiberg-Witten (SW) map. The WDW equation is explicitly dependent on the noncommutative parameters, $\\theta$ and $\\eta$. We obtain numerical solutions of the noncommutative WDW equation for different values of the noncommutative parameters. We conclude that the noncommutativity in the momenta sector leads to a damped wave function implying that this type of noncommmutativity can be relevant for a selection of possible initial states for the universe.

  7. Basic concepts in quantum computation

    CERN Document Server

    Ekert, A K; Inamori, H; Ekert, Artur; Hayden, Patrick; Inamori, Hitoshi

    2000-01-01

    Section headings: 1 Qubits, gates and networks 2 Quantum arithmetic and function evaluations 3 Algorithms and their complexity 4 From interferometers to computers 5 The first quantum algorithms 6 Quantum search 7 Optimal phase estimation 8 Periodicity and quantum factoring 9 Cryptography 10 Conditional quantum dynamics 11 Decoherence and recoherence 12 Concluding remarks

  8. Applications of quantum message sealing

    CERN Document Server

    Worley, G G

    2005-01-01

    In 2003, Bechmann-Pasquinucci introduced the concept of quantum seals, a quantum analogue to wax seals used to close letters and envelopes. Since then, some improvements on the method have been found. We first review the current quantum sealing techniques, then introduce and discuss potential applications of quantum message sealing, and conclude with some discussion of the limitations of quantum seals.

  9. Quantum Advantage in Communication Networks

    CERN Document Server

    De, Aditi Sen

    2011-01-01

    Quantum channels are known to provide qualitatively better information transfer capacities over their classical counterparts. Examples include quantum cryptography, quantum dense coding, and quantum teleportation. This is a short review on paradigmatic quantum communication protocols in both bipartite as well as multipartite scenarios.

  10. Quantum critical points in quantum impurity systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jung [Theoretische Physik III, Elektronische Korrelationen und Magnetismus, Universitaet Augsburg (Germany); Bulla, Ralf [Theoretische Physik III, Elektronische Korrelationen und Magnetismus, Universitaet Augsburg (Germany)]. E-mail: bulla@cpfs.mpg.de

    2005-04-30

    The numerical renormalization group method is used to investigate zero-temperature phase transitions in quantum impurity systems, in particular in the soft-gap Anderson model, where an impurity couples to a non-trivial fermionic bath. In this case, zero-temperature phase transitions occur between two different phases whose fixed points can be built up of non-interacting single-particle states. However, the quantum critical point cannot be described by non-interacting fermionic or bosonic excitations.

  11. Quantum critical points in quantum impurity systems

    Science.gov (United States)

    Lee, Hyun Jung; Bulla, Ralf

    2005-04-01

    The numerical renormalization group method is used to investigate zero-temperature phase transitions in quantum impurity systems, in particular in the soft-gap Anderson model, where an impurity couples to a non-trivial fermionic bath. In this case, zero-temperature phase transitions occur between two different phases whose fixed points can be built up of non-interacting single-particle states. However, the quantum critical point cannot be described by non-interacting fermionic or bosonic excitations.

  12. Decoherence in quantum mechanics and quantum cosmology

    Science.gov (United States)

    Hartle, James B.

    1992-01-01

    A sketch of the quantum mechanics for closed systems adequate for cosmology is presented. This framework is an extension and clarification of that of Everett and builds on several aspects of the post-Everett development. It especially builds on the work of Zeh, Zurek, Joos and Zeh, and others on the interactions of quantum systems with the larger universe and on the ideas of Griffiths, Omnes, and others on the requirements for consistent probabilities of histories.

  13. Quantum inertia stops superposition: Scan Quantum Mechanics

    Science.gov (United States)

    Gato-Rivera, Beatriz

    2017-08-01

    Scan Quantum Mechanics is a novel interpretation of some aspects of quantum mechanics in which the superposition of states is only an approximate effective concept. Quantum systems scan all possible states in the superposition and switch randomly and very rapidly among them. A crucial property that we postulate is quantum inertia, that increases whenever a constituent is added, or the system is perturbed with all kinds of interactions. Once the quantum inertia Iq reaches a critical value Icr for an observable, the switching among its different eigenvalues stops and the corresponding superposition comes to an end, leaving behind a system with a well defined value of that observable. Consequently, increasing the mass, temperature, gravitational strength, etc. of a quantum system increases its quantum inertia until the superposition of states disappears for all the observables and the system transmutes into a classical one. Moreover, the process could be reversible. Entanglement can only occur between quantum systems because an exact synchronization between the switchings of the systems involved must be established in the first place and classical systems do not have any switchings to start with. Future experiments might determine the critical inertia Icr corresponding to different observables, which translates into a critical mass Mcr for fixed environmental conditions as well as critical temperatures, critical electric and magnetic fields, etc. In addition, this proposal implies a new radiation mechanism from astrophysical objects with strong gravitational fields, giving rise to non-thermal synchrotron emission, that could contribute to neutron star formation. Superconductivity, superfluidity, Bose-Einstein condensates, and any other physical phenomena at very low temperatures must be reanalyzed in the light of this interpretation, as well as mesoscopic systems in general.

  14. Quantum ballistic evolution in quantum mechanics application to quantum computers

    CERN Document Server

    Benioff, P

    1996-01-01

    Quantum computers are important examples of processes whose evolution can be described in terms of iterations of single step operators or their adjoints. Based on this, Hamiltonian evolution of processes with associated step operators T is investigated here. The main limitation of this paper is to processes which evolve quantum ballistically, i.e. motion restricted to a collection of nonintersecting or distinct paths on an arbitrary basis. The main goal of this paper is proof of a theorem which gives necessary and sufficient conditions that T must satisfy so that there exists a Hamiltonian description of quantum ballistic evolution for the process, namely, that T is a partial isometry and is orthogonality preserving and stable on some basis. Simple examples of quantum ballistic evolution for quantum Turing machines with one and with more than one type of elementary step are discussed. It is seen that for nondeterministic machines the basis set can be quite complex with much entanglement present. It is also pr...

  15. Quantum Copy-Protection and Quantum Money

    CERN Document Server

    Aaronson, Scott

    2011-01-01

    Forty years ago, Wiesner proposed using quantum states to create money that is physically impossible to counterfeit, something that cannot be done in the classical world. However, Wiesner's scheme required a central bank to verify the money, and the question of whether there can be unclonable quantum money that anyone can verify has remained open since. One can also ask a related question, which seems to be new: can quantum states be used as copy-protected programs, which let the user evaluate some function f, but not create more programs for f? This paper tackles both questions using the arsenal of modern computational complexity. Our main result is that there exist quantum oracles relative to which publicly-verifiable quantum money is possible, and any family of functions that cannot be efficiently learned from its input-output behavior can be quantumly copy-protected. This provides the first formal evidence that these tasks are achievable. The technical core of our result is a "Complexity-Theoretic No-Clon...

  16. Quantum Common Causes and Quantum Causal Models

    Science.gov (United States)

    Allen, John-Mark A.; Barrett, Jonathan; Horsman, Dominic C.; Lee, Ciarán M.; Spekkens, Robert W.

    2017-07-01

    Reichenbach's principle asserts that if two observed variables are found to be correlated, then there should be a causal explanation of these correlations. Furthermore, if the explanation is in terms of a common cause, then the conditional probability distribution over the variables given the complete common cause should factorize. The principle is generalized by the formalism of causal models, in which the causal relationships among variables constrain the form of their joint probability distribution. In the quantum case, however, the observed correlations in Bell experiments cannot be explained in the manner Reichenbach's principle would seem to demand. Motivated by this, we introduce a quantum counterpart to the principle. We demonstrate that under the assumption that quantum dynamics is fundamentally unitary, if a quantum channel with input A and outputs B and C is compatible with A being a complete common cause of B and C , then it must factorize in a particular way. Finally, we show how to generalize our quantum version of Reichenbach's principle to a formalism for quantum causal models and provide examples of how the formalism works.

  17. Quantum random oracle model for quantum digital signature

    Science.gov (United States)

    Shang, Tao; Lei, Qi; Liu, Jianwei

    2016-10-01

    The goal of this work is to provide a general security analysis tool, namely, the quantum random oracle (QRO), for facilitating the security analysis of quantum cryptographic protocols, especially protocols based on quantum one-way function. QRO is used to model quantum one-way function and different queries to QRO are used to model quantum attacks. A typical application of quantum one-way function is the quantum digital signature, whose progress has been hampered by the slow pace of the experimental realization. Alternatively, we use the QRO model to analyze the provable security of a quantum digital signature scheme and elaborate the analysis procedure. The QRO model differs from the prior quantum-accessible random oracle in that it can output quantum states as public keys and give responses to different queries. This tool can be a test bed for the cryptanalysis of more quantum cryptographic protocols based on the quantum one-way function.

  18. Foundations of quantum theory and quantum information applications

    CERN Document Server

    Galvão, E F

    2002-01-01

    This thesis establishes a number of connections between foundational issues in quantum theory, and some quantum information applications. It starts with a review of quantum contextuality and non-locality, multipartite entanglement characterisation, and of a few quantum information protocols. Quantum non-locality and contextuality are shown to be essential for different implementations of quantum information protocols known as quantum random access codes and quantum communication complexity protocols. I derive sufficient experimental conditions for tests of these quantum properties. I also discuss how the distribution of quantum information through quantum cloning processes can be useful in quantum computing. Regarding entanglement characterisation, some results are obtained relating two problems, that of additivity of the relative entropy of entanglement, and that of identifying different types of tripartite entanglement in the asymptotic regime of manipulations of many copies of a given state. The thesis end...

  19. Origin of quantum randomness in the pilot wave quantum mechanics

    OpenAIRE

    Shtanov, Yuri

    1997-01-01

    We account for the origin of the laws of quantum probabilities in the de Broglie-Bohm (pilot wave) formulation of quantum theory by considering the property of ergodicity likely to characterise the dynamics of microscopic quantum systems.

  20. Macroscopic quantum resonators (MAQRO)

    CERN Document Server

    Kaltenbaek, Rainer; Kiesel, Nikolai; Romero-Isart, Oriol; Johann, Ulrich; Aspelmeyer, Markus

    2012-01-01

    Quantum physics challenges our understanding of the nature of physical reality and of space-time and suggests the necessity of radical revisions of their underlying concepts. Experimental tests of quantum phenomena involving massive macroscopic objects would provide novel insights into these fundamental questions. Making use of the unique environment provided by space, MAQRO aims at investigating this largely unexplored realm of macroscopic quantum physics. MAQRO has originally been proposed as a medium-sized fundamental-science space mission for the 2010 call of Cosmic Vision. MAQRO unites two experiments: DECIDE (DECoherence In Double-Slit Experiments) and CASE (Comparative Acceleration Sensing Experiment). The main scientific objective of MAQRO, which is addressed by the experiment DECIDE, is to test the predictions of quantum theory for quantum superpositions of macroscopic objects containing more than 10e8 atoms. Under these conditions, deviations due to various suggested alternative models to quantum th...

  1. Quantum physics meets biology.

    Science.gov (United States)

    Arndt, Markus; Juffmann, Thomas; Vedral, Vlatko

    2009-12-01

    Quantum physics and biology have long been regarded as unrelated disciplines, describing nature at the inanimate microlevel on the one hand and living species on the other hand. Over the past decades the life sciences have succeeded in providing ever more and refined explanations of macroscopic phenomena that were based on an improved understanding of molecular structures and mechanisms. Simultaneously, quantum physics, originally rooted in a world-view of quantum coherences, entanglement, and other nonclassical effects, has been heading toward systems of increasing complexity. The present perspective article shall serve as a "pedestrian guide" to the growing interconnections between the two fields. We recapitulate the generic and sometimes unintuitive characteristics of quantum physics and point to a number of applications in the life sciences. We discuss our criteria for a future "quantum biology," its current status, recent experimental progress, and also the restrictions that nature imposes on bold extrapolations of quantum theory to macroscopic phenomena.

  2. Surfing the quantum world

    CERN Document Server

    Levin, Frank S

    2017-01-01

    The ideas and phenomena of the quantum world are strikingly unlike those encountered in our visual world. Surfing the Quantum World shows why and how this is so. It does this via a historical review and a gentle introduction to the fundamental principles of quantum theory, whose core concepts and symbolic representations are used to explain not only "ordinary" microscopic phenomena like the properties of the hydrogen atom and the structure of the Periodic Table of the Elements, but also a variety of mind-bending phenomena. Readers will learn that particles such as electrons and photons can behave like waves, allowing them to be in two places simultaneously, why white dwarf and neutron stars are gigantic quantum objects, how the maximum height of mountains has a quantum basis, and why quantum objects can tunnel through seemingly impenetrable barriers. Included among the various interpretational issues addressed is whether Schrodinger's cat is ever both dead and alive.

  3. Quantum statistics on graphs

    CERN Document Server

    Harrison, JM; Robbins, JM; 10.1098/rspa.2010.0254

    2011-01-01

    Quantum graphs are commonly used as models of complex quantum systems, for example molecules, networks of wires, and states of condensed matter. We consider quantum statistics for indistinguishable spinless particles on a graph, concentrating on the simplest case of abelian statistics for two particles. In spite of the fact that graphs are locally one-dimensional, anyon statistics emerge in a generalized form. A given graph may support a family of independent anyon phases associated with topologically inequivalent exchange processes. In addition, for sufficiently complex graphs, there appear new discrete-valued phases. Our analysis is simplified by considering combinatorial rather than metric graphs -- equivalently, a many-particle tight-binding model. The results demonstrate that graphs provide an arena in which to study new manifestations of quantum statistics. Possible applications include topological quantum computing, topological insulators, the fractional quantum Hall effect, superconductivity and molec...

  4. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    1999-01-01

    of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra.Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dots states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used......Semiconductor quantum dots ("solid state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... to probe coherence times of exciton states and relaxation processes, both of which are important for future applications....

  5. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra. Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dot states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used......Semiconductor quantum dots ("solid-state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... to probe coherence times of exciton states and relaxation processes, both of which are important for future applications....

  6. Quantum Cosmology: Effective Theory

    CERN Document Server

    Bojowald, Martin

    2012-01-01

    Quantum cosmology has traditionally been studied at the level of symmetry-reduced minisuperspace models, analyzing the behavior of wave functions. However, in the absence of a complete full setting of quantum gravity and detailed knowledge of specific properties of quantum states, it remained difficult to make testable predictions. For quantum cosmology to be part of empirical science, it must allow for a systematic framework in which corrections to well-tested classical equations can be derived, with any ambiguities and ignorance sufficiently parameterized. As in particle and condensed-matter physics, a successful viewpoint is one of effective theories, adapted to specific issues one encounters in quantum cosmology. This review presents such an effective framework of quantum cosmology, taking into account, among other things, space-time structures, covariance, the problem of time and the anomaly issue.

  7. Practical quantum digital signature

    Science.gov (United States)

    Yin, Hua-Lei; Fu, Yao; Chen, Zeng-Bing

    2016-03-01

    Guaranteeing nonrepudiation, unforgeability as well as transferability of a signature is one of the most vital safeguards in today's e-commerce era. Based on fundamental laws of quantum physics, quantum digital signature (QDS) aims to provide information-theoretic security for this cryptographic task. However, up to date, the previously proposed QDS protocols are impractical due to various challenging problems and most importantly, the requirement of authenticated (secure) quantum channels between participants. Here, we present the first quantum digital signature protocol that removes the assumption of authenticated quantum channels while remaining secure against the collective attacks. Besides, our QDS protocol can be practically implemented over more than 100 km under current mature technology as used in quantum key distribution.

  8. Quantum information theory

    CERN Document Server

    Wilde, Mark M

    2017-01-01

    Developing many of the major, exciting, pre- and post-millennium developments from the ground up, this book is an ideal entry point for graduate students into quantum information theory. Significant attention is given to quantum mechanics for quantum information theory, and careful studies of the important protocols of teleportation, superdense coding, and entanglement distribution are presented. In this new edition, readers can expect to find over 100 pages of new material, including detailed discussions of Bell's theorem, the CHSH game, Tsirelson's theorem, the axiomatic approach to quantum channels, the definition of the diamond norm and its interpretation, and a proof of the Choi–Kraus theorem. Discussion of the importance of the quantum dynamic capacity formula has been completely revised, and many new exercises and references have been added. This new edition will be welcomed by the upcoming generation of quantum information theorists and the already established community of classical information theo...

  9. Quantum wave packet revivals

    CERN Document Server

    Robinett, R W

    2004-01-01

    The numerical prediction, theoretical analysis, and experimental verification of the phenomenon of wave packet revivals in quantum systems has flourished over the last decade and a half. Quantum revivals are characterized by initially localized quantum states which have a short-term, quasi-classical time evolution, which then can spread significantly over several orbits, only to reform later in the form of a quantum revival in which the spreading reverses itself, the wave packet relocalizes, and the semi-classical periodicity is once again evident. Relocalization of the initial wave packet into a number of smaller copies of the initial packet (`minipackets' or `clones') is also possible, giving rise to fractional revivals. Systems exhibiting such behavior are a fundamental realization of time-dependent interference phenomena for bound states with quantized energies in quantum mechanics and are therefore of wide interest in the physics and chemistry communities. We review the theoretical machinery of quantum w...

  10. Quantum Cryptography in Practice

    CERN Document Server

    Elliott, C; Troxel, G; Elliott, Chip; Pearson, David; Troxel, Gregory

    2003-01-01

    BBN, Harvard, and Boston University are building the DARPA Quantum Network, the world's first network that delivers end-to-end network security via high-speed Quantum Key Distribution, and testing that Network against sophisticated eavesdropping attacks. The first network link has been up and steadily operational in our laboratory since December 2002. It provides a Virtual Private Network between private enclaves, with user traffic protected by a weak-coherent implementation of quantum cryptography. This prototype is suitable for deployment in metro-size areas via standard telecom (dark) fiber. In this paper, we introduce quantum cryptography, discuss its relation to modern secure networks, and describe its unusual physical layer, its specialized quantum cryptographic protocol suite (quite interesting in its own right), and our extensions to IPsec to integrate it with quantum cryptography.

  11. Testing loop quantum cosmology

    Science.gov (United States)

    Wilson-Ewing, Edward

    2017-03-01

    Loop quantum cosmology predicts that quantum gravity effects resolve the big-bang singularity and replace it by a cosmic bounce. Furthermore, loop quantum cosmology can also modify the form of primordial cosmological perturbations, for example by reducing power at large scales in inflationary models or by suppressing the tensor-to-scalar ratio in the matter bounce scenario; these two effects are potential observational tests for loop quantum cosmology. In this article, I review these predictions and others, and also briefly discuss three open problems in loop quantum cosmology: its relation to loop quantum gravity, the trans-Planckian problem, and a possible transition from a Lorentzian to a Euclidean space-time around the bounce point.

  12. Quantum isometry groups

    CERN Document Server

    Goswami, Debashish

    2016-01-01

    This book offers an up-to-date overview of the recently proposed theory of quantum isometry groups. Written by the founders, it is the first book to present the research on the “quantum isometry group”, highlighting the interaction of noncommutative geometry and quantum groups, which is a noncommutative generalization of the notion of group of isometry of a classical Riemannian manifold. The motivation for this generalization is the importance of isometry groups in both mathematics and physics. The framework consists of Alain Connes’ “noncommutative geometry” and the operator-algebraic theory of “quantum groups”. The authors prove the existence of quantum isometry group for noncommutative manifolds given by spectral triples under mild conditions and discuss a number of methods for computing them. One of the most striking and profound findings is the non-existence of non-classical quantum isometry groups for arbitrary classical connected compact manifolds and, by using this, the authors explicitl...

  13. Reversible quantum cellular automata

    CERN Document Server

    Schumacher, B

    2004-01-01

    We define quantum cellular automata as infinite quantum lattice systems with discrete time dynamics, such that the time step commutes with lattice translations and has strictly finite propagation speed. In contrast to earlier definitions this allows us to give an explicit characterization of all local rules generating such automata. The same local rules also generate the global time step for automata with periodic boundary conditions. Our main structure theorem asserts that any quantum cellular automaton is structurally reversible, i.e., that it can be obtained by applying two blockwise unitary operations in a generalized Margolus partitioning scheme. This implies that, in contrast to the classical case, the inverse of a nearest neighbor quantum cellular automaton is again a nearest neighbor automaton. We present several construction methods for quantum cellular automata, based on unitaries commuting with their translates, on the quantization of (arbitrary) reversible classical cellular automata, on quantum c...

  14. Quantum Randi Challenge

    CERN Document Server

    Vongehr, Sascha

    2012-01-01

    Violations of Bell type inequalities in quantum experiments disprove all relativistic micro causal, classically real models. Desperate attempts at saving classicality retreated to claiming what Shimony calls a conspiracy. It is time to embrace the quantum paradigm instead of being stuck in defending it against positions on par with the belief in divinely planted fossils. However, different from 'quantum-magic' pseudoscience, there is resistance against quantum mechanics among scientific literate audiences, and it is growing. The Quantum Randi Challenge is designed to help scientists and educators discredit local realistic models and related attacks against quantum physics. Its 'Randi-type' properties are ensured via a simple computer game that can be made attractive and understandable to lay people. We introduce the general concept of a 'James Randi type' challenge as a tool for science outreach aimed against the spread of pseudoscience. This is a challenge which, according to the laws of nature as known to s...

  15. Quantum mechanics for pedestrians

    CERN Document Server

    Pade, Jochen

    2014-01-01

    This book provides an introduction into the fundamentals of non-relativistic quantum mechanics. In Part 1, the essential principles are developed. Applications and extensions of the formalism can be found in Part 2. The book includes not only material that is presented in traditional textbooks on quantum mechanics, but also discusses in detail current issues such as interaction-free quantum measurements, neutrino oscillations, various topics in the field of quantum information as well as fundamental problems and epistemological questions, such as the measurement problem, entanglement, Bell's inequality, decoherence, and the realism debate. A chapter on current interpretations of quantum mechanics concludes the book. To develop quickly and clearly the main principles of quantum mechanics and its mathematical formulation, there is a systematic change between wave mechanics and algebraic representation in the first chapters. The required mathematical tools are introduced step by step. Moreover, the appendix coll...

  16. A Universal Quantum Network Quantum Central Processing Unit

    Institute of Scientific and Technical Information of China (English)

    WANG An-Min

    2001-01-01

    A new construction scheme of a universal quantum network which is compatible with the known quantum gate- assembly schemes is proposed. Our quantum network is standard, easy-assemble, reusable, scalable and even potentially programmable. Moreover, we can construct a whole quantum network to implement the generalquantum algorithm and quantum simulation procedure. In the above senses, it is a realization of the quantum central processing unit.

  17. Duality quantum algorithm efficiently simulates open quantum systems

    OpenAIRE

    Shi-Jie Wei; Dong Ruan; Gui-Lu Long

    2016-01-01

    Because of inevitable coupling with the environment, nearly all practical quantum systems are open system, where the evolution is not necessarily unitary. In this paper, we propose a duality quantum algorithm for simulating Hamiltonian evolution of an open quantum system. In contrast to unitary evolution in a usual quantum computer, the evolution operator in a duality quantum computer is a linear combination of unitary operators. In this duality quantum algorithm, the time evolution of the op...

  18. Quantum optics with quantum dots in photonic nanowires

    DEFF Research Database (Denmark)

    We will review recent studies performed on InAs quantum dots embedded in GaAs photonic wires, which highlight the strong interest of the photonic wire geometry for quantum optics experiments and quantum optoelectronic devices.......We will review recent studies performed on InAs quantum dots embedded in GaAs photonic wires, which highlight the strong interest of the photonic wire geometry for quantum optics experiments and quantum optoelectronic devices....

  19. Quantum-enhanced Sensing and Efficient Quantum Computation

    Science.gov (United States)

    2015-07-27

    Quantum -enhanced sensing and efficient quantum computation Ian Walmsley THE UNIVERSITY OF...COVERED (From - To) 1 February 2013 - 31 January 2015 4. TITLE AND SUBTITLE Quantum -enhanced sensing and efficient quantum computation 5a. CONTRACT...1895616013 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 Final report for “ Quantum ‐Enhanced Sensing and Efficient  Quantum   Computation

  20. Quantum Optics with Quantum Dots in Photonic Nanowires

    DEFF Research Database (Denmark)

    Gérard, J.-M.; Claudon, J.; Bleuse, J.;

    2011-01-01

    We review recent studies performed on InAs quantum dots embedded in GaAs photonic wires, which highlight the strong interest of the photonic wire geometry for quantum optics experiments and quantum optoelectronic devices.......We review recent studies performed on InAs quantum dots embedded in GaAs photonic wires, which highlight the strong interest of the photonic wire geometry for quantum optics experiments and quantum optoelectronic devices....

  1. The Category of Quantum Frames%Quantum frame范畴

    Institute of Scientific and Technical Information of China (English)

    李娟

    2011-01-01

    In this paper , we introduce some basic concepts on a quantum frame, obtain the result that the quotient set of a quantum frame on a congruence relation is a quantum frame, and give some categorical ? Properties of quantum frame.%给出有关quantum frame的一些基本概念,证明quantum frame关于同余关系的商集为quantum frame,讨论quantum frame的若干范畴性质.

  2. Quantum Communication Scheme Using Non-symmetric Quantum Channel

    Institute of Scientific and Technical Information of China (English)

    CAO Hai-Jing; CHEN Zhong-Hua; SONG He-Shan

    2008-01-01

    A theoretical quantum communication scheme based on entanglement swapping and superdense coding is proposed with a 3-dimensional Bell state and 2-dimensional Bell state function as quantum channel quantum key distribution and quantum secure direct communication can be simultaneously accomplished in the scheme. The scheme is secure and has high source capacity. At last, we generalize the quantum communication scheme to d-dimensional quantum channel.

  3. Relating quantum discord with the quantum dense coding capacity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Qiu, Liang, E-mail: lqiu@cumt.edu.cn; Li, Song; Zhang, Chi [China University of Mining and Technology, School of Sciences (China); Ye, Bin [China University of Mining and Technology, School of Information and Electrical Engineering (China)

    2015-01-15

    We establish the relations between quantum discord and the quantum dense coding capacity in (n + 1)-particle quantum states. A necessary condition for the vanishing discord monogamy score is given. We also find that the loss of quantum dense coding capacity due to decoherence is bounded below by the sum of quantum discord. When these results are restricted to three-particle quantum states, some complementarity relations are obtained.

  4. Holography and Quantum Mechanics

    CERN Document Server

    Wang, X J

    2002-01-01

    It is illustrated that quantum mechanics can be interpreted as holographic projection of higher dimension classical gravity. In this explanation every quantum path in D-dimension is dual to a classical path of (D+1)-dimension gravity under definite holographic projection. I consider 2-dimension non-relativitic free particle and harmonic oscillator as two examples, and find their gravity dual. I conjecture that every quantum mechanics system has their dual gravity description.

  5. Measuring quantumness via anticommutators

    CERN Document Server

    Fazio, Rosario; Pascazio, Saverio; Vedral, Vlatko; Yuasa, Kazuya

    2012-01-01

    We introduce a method to witness the quantumness of a system. The method relies on the fact that the anticommutator of two classical states is always positive. We show that there is always a nonpositive anticommutator due to any two quantum states. We notice that interference depends on the trace of the anticommutator of two states and it is therefore more natural to detect quantumness by looking at anticommutators of states rather than their commutators.

  6. Virtual Quantum Subsystems

    OpenAIRE

    Zanardi, Paolo

    2001-01-01

    The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set $\\cal A$ of operationally relevant observables. The algebraic structure of $\\cal A$ selects a preferred tensor product structure i.e., a partition into subsystems. The notion of compoundness for quantum system is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies

  7. Virtual quantum subsystems.

    Science.gov (United States)

    Zanardi, P

    2001-08-13

    The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set A of operationally relevant observables. The algebraic structure of A selects a preferred tensor product structure, i.e., a partition into subsystems. The notion of compoundness for quantum systems is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies

  8. Quantum mechanics in chemistry

    CERN Document Server

    Schatz, George C

    2002-01-01

    Intended for graduate and advanced undergraduate students, this text explores quantum mechanical techniques from the viewpoint of chemistry and materials science. Dynamics, symmetry, and formalism are emphasized. An initial review of basic concepts from introductory quantum mechanics is followed by chapters examining symmetry, rotations, and angular momentum addition. Chapter 4 introduces the basic formalism of time-dependent quantum mechanics, emphasizing time-dependent perturbation theory and Fermi's golden rule. Chapter 5 sees this formalism applied to the interaction of radiation and matt

  9. Quantum identification system

    OpenAIRE

    Dusek, Miloslav; Haderka, Ondrej; Hendrych, Martin; Myska, Robert

    1998-01-01

    A secure quantum identification system combining a classical identification procedure and quantum key distribution is proposed. Each identification sequence is always used just once and new sequences are ``refuelled'' from a shared provably secret key transferred through the quantum channel. Two identification protocols are devised. The first protocol can be applied when legitimate users have an unjammable public channel at their disposal. The deception probability is derived for the case of ...

  10. Open quantum system identification

    CERN Document Server

    Schirmer, Sophie G; Zhou, Weiwei; Gong, Erling; Zhang, Ming

    2012-01-01

    Engineering quantum systems offers great opportunities both technologically and scientifically for communication, computation, and simulation. The construction and operation of large scale quantum information devices presents a grand challenge and a major issue is the effective control of coherent dynamics. This is often in the presence of decoherence which further complicates the task of determining the behaviour of the system. Here, we show how to determine open system Markovian dynamics of a quantum system with restricted initialisation and partial output state information.

  11. Microwave Quantum Illumination

    Science.gov (United States)

    2016-07-29

    Df Introduction .– Entanglement is the foundation of many quantum information protocols [1–3], but it is easily de- stroyed by environmental noise that...1Institute for Quantum Information , RWTH Aachen University, 52056 Aachen, Germany 2Quantum Information Processing Group, Raytheon BBN Technologies...entanglement, theory showed that the QI system will significantly outperform a clas- sical (coherent-state) system of the same transmitted energy [5–7

  12. Quantum Spin Gyroscope

    Science.gov (United States)

    2015-07-15

    Progress Report (ONR Award No. N00014-14-1-0804) Quantum Spin Gyroscope August 2014-July 2015 Report Type: Annual Report Primary Contact E-mail... Quantum Spin Gyroscope Grant/Contract Number: N00014-14-1-0804 Principal Investigator Name: Paola Cappellaro Program Manager: Richard Tommy Willis...required large volumes. Our project aims at overcoming these drawbacks by developing a novel solid-state quantum spin gyro- scope associated with the

  13. Fundamentals of quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Klauder, J R [Department of Physics and Department of Mathematics, University of Florida, Gainesville FL 32611-8440 (United States)

    2007-11-15

    The outline of a recent approach to quantum gravity is presented. Novel ingredients include: (1) Affine kinematical variables; (2) Affine coherent states; (3) Projection operator approach toward quantum constraints; (4) Continuous-time regularized functional integral representation without/with constraints; and (5) Hard core picture of nonrenormalizability. The 'diagonal representation' for operator representations, introduced by Sudarshan into quantum optics, arises naturally within this program.

  14. Quantum Monte Carlo simulation

    OpenAIRE

    Wang, Yazhen

    2011-01-01

    Contemporary scientific studies often rely on the understanding of complex quantum systems via computer simulation. This paper initiates the statistical study of quantum simulation and proposes a Monte Carlo method for estimating analytically intractable quantities. We derive the bias and variance for the proposed Monte Carlo quantum simulation estimator and establish the asymptotic theory for the estimator. The theory is used to design a computational scheme for minimizing the mean square er...

  15. Quantum steering without inequalities

    CERN Document Server

    Chen, Jing-Ling; Wu, Chunfeng; Su, Hong-Yi; Cabello, Adan; Kwek, L C; Oh, C H

    2012-01-01

    We show that, for any two-qubit state, quantum steering can be proven without testing the violation of steering inequalities. We show that steerability is proven if Bob's normalized conditional states after Alice's measurements are pure. This method, which may be seen as the quantum steering analog of Greenberger-Horne-Zeilinger-like tests of Bell nonlocality without Bell inequalities, offers advantages with respect to the existing methods for experimentally testing quantum steering.

  16. Elementary Nonrelativistic Quantum Mechanics

    CERN Document Server

    Rosu, H C

    2000-01-01

    This is a graduate course on elementary quantum mechanics written for the benefit of undergraduate and graduate students. It is the English version of physics/0003106, which I did at the suggestion of several students from different countries. The topics included refer to the postulates of quantum mechanics, one-dimensional barriers and wells, angular momentum and spin, WKB method, harmonic oscillator, hydrogen atom, quantum scattering, and partial waves

  17. Problems in quantum mechanics

    CERN Document Server

    Gol'dman, I I

    2010-01-01

    A comprehensive collection of problems of varying degrees of difficulty in nonrelativistic quantum mechanics, with answers and completely worked-out solutions. Among the topics: one-dimensional motion, transmission through a potential barrier, commutation relations, angular momentum and spin, and motion of a particle in a magnetic field. An ideal adjunct to any textbook in quantum mechanics, useful in courses in atomic and nuclear physics, mathematical methods in physics, quantum statistics and applied differential equations. 1961 edition.

  18. Parallelizing quantum circuit synthesis

    OpenAIRE

    Di Matteo, Olivia; Mosca, Michele

    2016-01-01

    Quantum circuit synthesis is the process in which an arbitrary unitary operation is decomposed into a sequence of gates from a universal set, typically one which a quantum computer can implement both efficiently and fault-tolerantly. As physical implementations of quantum computers improve, the need is growing for tools which can effectively synthesize components of the circuits and algorithms they will run. Existing algorithms for exact, multi-qubit circuit synthesis scale exponentially in t...

  19. Relational Quantum Cosmology

    CERN Document Server

    Vidotto, Francesca

    2015-01-01

    The application of quantum theory to cosmology raises a number of conceptual questions, such as the role of the quantum-mechanical notion of "observer" or the absence of a time variable in the Wheeler-DeWitt equation. I point out that a relational formulation of quantum mechanics, and more in general the observation that evolution is always relational, provides a coherent solution to this tangle of problems.

  20. Relativistic quantum revivals.

    Science.gov (United States)

    Strange, P

    2010-03-26

    Quantum revivals are now a well-known phenomena within nonrelativistic quantum theory. In this Letter we display the effects of relativity on revivals and quantum carpets. It is generally believed that revivals do not occur within a relativistic regime. Here we show that while this is generally true, it is possible, in principle, to set up wave packets with specific mathematical properties that do exhibit exact revivals within a fully relativistic theory.

  1. Quantum mechanical Carnot engine

    CERN Document Server

    Bender, C M; Meister, B K

    2000-01-01

    A cyclic thermodynamic heat engine runs most efficiently if it is reversible. Carnot constructed such a reversible heat engine by combining adiabatic and isothermal processes for a system containing an ideal gas. Here, we present an example of a cyclic engine based on a single quantum-mechanical particle confined to a potential well. The efficiency of this engine is shown to equal the Carnot efficiency because quantum dynamics is reversible. The quantum heat engine has a cycle consisting of adiabatic and isothermal quantum processes that are close analogues of the corresponding classical processes.

  2. Two Quantum Polytropic Cycles

    Science.gov (United States)

    Arias-Hernández, L. A.; Morales-Serrano, A. F.

    2002-11-01

    In this work we follow the Bender et al paper [1] to study the quantum analogues of the Stirling and Ericsson polytropic cycles. In the context of the classical thermodynamics, the Stirling and Ericsson cycles correspond to reversible heat engines with two isothermal processes joined by two polytropic branches which occur in a device called regenerator. If this device is an ideal one, the efficiency of these cycles is the Carnot efficiency. Here, we introduce the quantum analogues of the Stirling and Ericsson cycles, the first one based on a double square potential well with a finite potential barrier, since in this system the tunnel effect could be the analogue to the regeneration classical process, therefore the isochoric quantum branches would really correspond to an internal energy storage, and the last one with an unknown system where the isobaric quantum processes don't induce changes in its quantum state. With these systems the quantum engines have cycles consisting of polytropic and isothermal quantum processes analogues to the corresponding classical processes. We show that in both cases the quantum cycles have an efficiency given by ηCQM = 1 - EC/EH, which is the same expression for the quantum analogue of the Carnot cycle studied by Bender.

  3. Understanding quantum phase transitions

    CERN Document Server

    Carr, Lincoln

    2010-01-01

    Quantum phase transitions (QPTs) offer wonderful examples of the radical macroscopic effects inherent in quantum physics: phase changes between different forms of matter driven by quantum rather than thermal fluctuations, typically at very low temperatures. QPTs provide new insight into outstanding problems such as high-temperature superconductivity and display fundamental aspects of quantum theory, such as strong correlations and entanglement. Over the last two decades, our understanding of QPTs has increased tremendously due to a plethora of experimental examples, powerful new numerical meth

  4. Quantum Communication Technology

    CERN Document Server

    Gisin, Nicolas

    2010-01-01

    Quantum communication is built on a set of disruptive concepts and technologies. It is driven by fascinating physics and by promising applications. It requires a new mix of competencies, from telecom engineering to theoretical physics, from theoretical computer science to mechanical and electronic engineering. First applications have already found their way to niche markets and university labs are working on futuristic quantum networks, but most of the surprises are still ahead of us. Quantum communication, and more generally quantum information science and technologies, are here to stay and will have a profound impact on the XXI century.

  5. Measurement in quantum physics

    Energy Technology Data Exchange (ETDEWEB)

    Danos, M. [Illinois Univ., Chicago, IL (United States); Kieu, T.D. [Melbourne Univ., Parkville, VIC (Australia). School of Physics]|[Columbia Univ., New York, NY (United States). Dept. of Physics

    1997-06-01

    The conceptual problems in quantum mechanics - including the collapse of the wave functions, the particle-wave duality, the meaning of measurement-arise from the need to ascribe particle character to the wave function, which describes only the wave aspects. It is demonstrated that all these problems can be resolved when working instead with quantum fields, which have both wave and particle character. The predictions of quantum physics, including Bell`s inequalities, remain unchanged from the standard treatments of quantum mechanics. 16 refs.

  6. Quantum image processing?

    Science.gov (United States)

    Mastriani, Mario

    2017-01-01

    This paper presents a number of problems concerning the practical (real) implementation of the techniques known as quantum image processing. The most serious problem is the recovery of the outcomes after the quantum measurement, which will be demonstrated in this work that is equivalent to a noise measurement, and it is not considered in the literature on the subject. It is noteworthy that this is due to several factors: (1) a classical algorithm that uses Dirac's notation and then it is coded in MATLAB does not constitute a quantum algorithm, (2) the literature emphasizes the internal representation of the image but says nothing about the classical-to-quantum and quantum-to-classical interfaces and how these are affected by decoherence, (3) the literature does not mention how to implement in a practical way (at the laboratory) these proposals internal representations, (4) given that quantum image processing works with generic qubits, this requires measurements in all axes of the Bloch sphere, logically, and (5) among others. In return, the technique known as quantum Boolean image processing is mentioned, which works with computational basis states (CBS), exclusively. This methodology allows us to avoid the problem of quantum measurement, which alters the results of the measured except in the case of CBS. Said so far is extended to quantum algorithms outside image processing too.

  7. Quantum physics. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Scheck, Florian [Mainz Univ. (Germany). Inst. fuer Physik, Theoretische Elementarteilchenphysik

    2013-11-01

    New edition with added sections on nonlinear quantum mechanics and path integral methods in field theory. Contains an encyclopedic coverage from uncertainty relation to many-body systems, from symmetries to electroweak interation. Includes problems, partly with solutions, partly with hints towards solutions. Starting with basic principles and providing the framework all vital elements of nonrelativistic quantum mechanics are explained, even an introduction to quantum electrodynamics is included. Scheck's Quantum Physics presents a comprehensive introductory treatment, ideally suited for a two-semester course. Part One covers the basic principles and prime applications of quantum mechanics, from the uncertainty relations to many-body systems. Part Two introduces to relativistic quantum field theory and ranges from symmetries in quantum physics to electroweak interactions. Numerous worked-out examples as well as exercises, with solutions or hints, enables the book's use as an accompanying text for courses, and also for independent study. For both parts, the necessary mathematical framework is treated in adequate form and detail. The book ends with appendices covering mathematical fundamentals and enrichment topics, plus selected biographical notes on pioneers of quantum mechanics and quantum field theory. The new edition was thoroughly revised and now includes new sections on quantization using the path integral method and on deriving generalized path integrals for bosonic and fermionic fields.

  8. Quantum information and computing

    CERN Document Server

    Ohya, M; Watanabe, N

    2006-01-01

    The main purpose of this volume is to emphasize the multidisciplinary aspects of this very active new line of research in which concrete technological and industrial realizations require the combined efforts of experimental and theoretical physicists, mathematicians and engineers. Contents: Coherent Quantum Control of ?-Atoms through the Stochastic Limit (L Accardi et al.); Recent Advances in Quantum White Noise Calculus (L Accardi & A Boukas); Joint Extension of States of Fermion Subsystems (H Araki); Fidelity of Quantum Teleportation Model Using Beam Splittings (K-H Fichtner et al.); Quantum

  9. Quantum Physics in School.

    Science.gov (United States)

    Lawrence, I.

    1996-01-01

    Discusses a teaching strategy for introducing quantum ideas into the school classroom using modern devices. Develops the concepts of quantization, wave-particle duality, nonlocality, and tunneling. (JRH)

  10. On quantum statistical inference

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Gill, Richard D.; Jupp, Peter E.

    Recent developments in the mathematical foundations of quantum mechanics have brought the theory closer to that of classical probability and statistics. On the other hand, the unique character of quantum physics sets many of the questions addressed apart from those met classically in stochastics....... Furthermore, concurrent advances in experimental techniques and in the theory of quantum computation have led to a strong interest in questions of quantum information, in particular in the sense of the amount of information about unknown parameters in given observational data or accessible through various...

  11. Allowable Generalized Quantum Gates

    Institute of Scientific and Technical Information of China (English)

    LONG Gui-Lu; LIU Yang; WANG Chuan

    2009-01-01

    In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form Σ(d-1)(i=0)piUi, and the Pi's are complex numbers with module less or equal to I and constrained by |Σipi|≤1.

  12. Quantum Transport in Semiconductors

    Science.gov (United States)

    1991-10-01

    SRS i 91 4. TITLE AND SUBTITLE Quantum Transport in Semiconductors 5. FUNDING NUMBER söMtos-rizk-ooss 6. AUTHOR(S) D. K. Ferry ©fte ELECTE...OF ABSTRACT UL NSN 7540-01-280-5500 O 1 9 Standard Form 298 (Rev. 2-89) Presented by ANSI Std «9-18 298-102 Final Report Quantum Transport in... Quantum Transport in Semiconductor Devices This final report describes a program of research investigating quantum effects which become important in

  13. Lectures on quantum mechanics

    CERN Document Server

    Dirac, Paul A M

    2001-01-01

    The author of this concise, brilliant series of lectures on mathematical methods in quantum mechanics was one of the shining intellects in the field, winning a Nobel prize in 1933 for his pioneering work in the quantum mechanics of the atom. Beyond that, he developed the transformation theory of quantum mechanics (which made it possible to calculate the statistical distribution of certain variables), was one of the major authors of the quantum theory of radiation, codiscovered the Fermi-Dirac statistics, and predicted the existence of the positron.The four lectures in this book were delivered

  14. Resolution of quantum singularities

    Science.gov (United States)

    Konkowski, Deborah; Helliwell, Thomas

    2017-01-01

    A review of quantum singularities in static and conformally static spacetimes is given. A spacetime is said to be quantum mechanically non-singular if a quantum wave packet does not feel, in some sense, the presence of a singularity; mathematically, this means that the wave operator is essentially self-adjoint on the space of square integrable functions. Spacetimes with classical mild singularities (quasiregular ones) to spacetimes with classical strong curvature singularities have been tested. Here we discuss the similarities and differences between classical singularities that are healed quantum mechanically and those that are not. Possible extensions of the mathematical technique to more physically realistic spacetimes are discussed.

  15. Introductory Quantum Optics

    Science.gov (United States)

    Gerry, Christopher; Knight, Peter

    2004-10-01

    1. Introduction; 2. Field quantization; 3. Coherent states; 4. Emission and absorption of radiation by atoms; 5. Quantum coherence functions; 6. Beam splitters and interferometers; 7. Nonclassical light; 8. Dissipative interactions and decoherence; 9. Optical test of quantum mechanics; 10. Experiments in cavity QED and with trapped ions; 11. Applications of entanglement: Heisenberg-limited interferometry and quantum information processing; Appendix A. The density operator, entangled states, the Schmidt decomposition, and the von Neumann entropy; Appendix B. Quantum measurement theory in a (very small) nutshell; Appendix C. Derivation of the effective Hamiltonian for dispersive (far off-resonant) interactions; Appendix D. Nonlinear optics and spontaneous parametric down-conversion.

  16. Integrated photonic quantum walks

    Science.gov (United States)

    Gräfe, Markus; Heilmann, René; Lebugle, Maxime; Guzman-Silva, Diego; Perez-Leija, Armando; Szameit, Alexander

    2016-10-01

    Over the last 20 years quantum walks (QWs) have gained increasing interest in the field of quantum information science and processing. In contrast to classical walkers, quantum objects exhibit intrinsic properties like non-locality and non-classical many-particle correlations, which renders QWs a versatile tool for quantum simulation and computation as well as for a deeper understanding of genuine quantum mechanics. Since they are highly controllable and hardly interact with their environment, photons seem to be ideally suited quantum walkers. In order to study and exploit photonic QWs, lattice structures that allow low loss coherent evolution of quantum states are demanded. Such requirements are perfectly met by integrated optical waveguide devices that additionally allow a substantial miniaturization of experimental settings. Moreover, by utilizing the femtosecond direct laser writing technique three-dimensional waveguide structures are capable of analyzing QWs also on higher dimensional geometries. In this context, advances and findings of photonic QWs are discussed in this review. Various concepts and experimental results are presented covering, such as different quantum transport regimes, the Boson sampling problem, and the discrete fractional quantum Fourier transform.

  17. The quantum Arnold transformation

    Science.gov (United States)

    Aldaya, V.; Cossío, F.; Guerrero, J.; López-Ruiz, F. F.

    2011-02-01

    Using a quantum version of the Arnold transformation of classical mechanics, all quantum dynamical systems whose classical equations of motion are non-homogeneous linear second-order ordinary differential equations, including systems with friction linear in velocity, can be related to the quantum free-particle dynamical system. This transformation provides a basic (Heisenberg-Weyl) algebra of quantum operators, along with well-defined Hermitian operators which can be chosen as evolution-like observables and complete the entire Schrödinger algebra. It also proves to be very helpful in performing certain computations quickly, to obtain, for example, wavefunctions and closed analytic expressions for time-evolution operators.

  18. The odd quantum

    CERN Document Server

    Treiman, Samuel Bard

    1999-01-01

    This is a rare and much-needed book: a concise but comprehensive account of quantum mechanics for popular science readers written by a respected physicist. Sam Treiman--internationally renowned for his work in particle physics--makes quantum mechanics accessible to nonspecialists. Combining mastery of the material with clear, elegant prose and infectious enthusiasm, he conveys the substance, methods, and profound oddities of the field.Treiman begins with an overview of quantum mechanics. He sketches the early development of the field by Einstein, Bohr, Heisenberg, Schrödinger, and others, and he makes clear how the quantum outlook flies in the face of common sense

  19. On quantum statistical inference

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Gill, Richard D.; Jupp, Peter E.

    Recent developments in the mathematical foundations of quantum mechanics have brought the theory closer to that of classical probability and statistics. On the other hand, the unique character of quantum physics sets many of the questions addressed apart from those met classically in stochastics....... Furthermore, concurrent advances in experimental techniques and in the theory of quantum computation have led to a strong interest in questions of quantum information, in particular in the sense of the amount of information about unknown parameters in given observational data or accessible through various...

  20. Facing quantum mechanical reality.

    Science.gov (United States)

    Rohrlich, F

    1983-09-23

    Two recent precision experiments provide conclusive evidence against any local hidden variables theory and in favor of standard quantum mechanics. Therefore the epistemology and the ontology of quantum mechanics must now be taken more seriously than ever before. The consequences of the standard interpretation of quantum mechanics are summarized in nontechnical language. The implications of the finiteness of Planck's constant (h > 0) for the quantum world are as strange as the implications of the finiteness of the speed of light (c < infinity for space and time in relativity theory. Both lead to realities beyond our common experience that cannot be rejected.

  1. Quantum chemistry an introduction

    CERN Document Server

    Kauzmann, Walter

    2013-01-01

    Quantum Chemistry: An Introduction provides information pertinent to the fundamental aspects of quantum mechanics. This book presents the theory of partial differentiation equations by using the classical theory of vibrations as a means of developing physical insight into this essential branch of mathematics.Organized into five parts encompassing 16 chapters, this book begins with an overview of how quantum mechanical deductions are made. This text then describes the achievements and limitations of the application of quantum mechanics to chemical problems. Other chapters provide a brief survey

  2. Quantum communications: Teleportation becomes streetwise

    Science.gov (United States)

    Grosshans, Frédéric

    2016-10-01

    Quantum teleportation is at the heart of many quantum information protocols. Two teams have now performed it over several kilometres of metropolitan fibre networks, paving the way for future quantum technologies on the city scale.

  3. Quantum rekenen: Quantumcomputers en qubits

    NARCIS (Netherlands)

    Hensen, B.J.; Hanson, R.

    2013-01-01

    De quantum computer is een computer gebaseerd op quantum bits, kortweg qubits. Dat zijn bits die fysiek gemaakt zijn van quantum systemen, met de speciale eigenschap dat ze in een superpositie tussen twee toestanden kunnen zijn.

  4. Security of Quantum Key Distribution

    CERN Document Server

    Renner, R

    2005-01-01

    We propose various new techniques in quantum information theory, including a de Finetti style representation theorem for finite symmetric quantum states. As an application, we give a proof for the security of quantum key distribution which applies to arbitrary protocols.

  5. Finite and profinite quantum systems

    CERN Document Server

    Vourdas, Apostolos

    2017-01-01

    This monograph provides an introduction to finite quantum systems, a field at the interface between quantum information and number theory, with applications in quantum computation and condensed matter physics. The first major part of this monograph studies the so-called `qubits' and `qudits', systems with periodic finite lattice as position space. It also discusses the so-called mutually unbiased bases, which have applications in quantum information and quantum cryptography. Quantum logic and its applications to quantum gates is also studied. The second part studies finite quantum systems, where the position takes values in a Galois field. This combines quantum mechanics with Galois theory. The third part extends the discussion to quantum systems with variables in profinite groups, considering the limit where the dimension of the system becomes very large. It uses the concepts of inverse and direct limit and studies quantum mechanics on p-adic numbers. Applications of the formalism include quantum optics and ...

  6. Quantum computer for dummies (in Russian)

    OpenAIRE

    Grozin, Andrey

    2011-01-01

    An introduction (in Russian) to quantum computers, quantum cryptography, and quantum teleportation for students who have no previous knowledge of these subjects, but know quantum mechanics. Several simple examples are considered in detail using the quantum computer emulator QCL.

  7. Relativistic quantum information

    Science.gov (United States)

    Mann, R. B.; Ralph, T. C.

    2012-11-01

    Over the past few years, a new field of high research intensity has emerged that blends together concepts from gravitational physics and quantum computing. Known as relativistic quantum information, or RQI, the field aims to understand the relationship between special and general relativity and quantum information. Since the original discoveries of Hawking radiation and the Unruh effect, it has been known that incorporating the concepts of quantum theory into relativistic settings can produce new and surprising effects. However it is only in recent years that it has become appreciated that the basic concepts involved in quantum information science undergo significant revision in relativistic settings, and that new phenomena arise when quantum entanglement is combined with relativity. A number of examples illustrate that point. Quantum teleportation fidelity is affected between observers in uniform relative acceleration. Entanglement is an observer-dependent property that is degraded from the perspective of accelerated observers moving in flat spacetime. Entanglement can also be extracted from the vacuum of relativistic quantum field theories, and used to distinguish peculiar motion from cosmological expansion. The new quantum information-theoretic framework of quantum channels in terms of completely positive maps and operator algebras now provides powerful tools for studying matters of causality and information flow in quantum field theory in curved spacetimes. This focus issue provides a sample of the state of the art in research in RQI. Some of the articles in this issue review the subject while others provide interesting new results that will stimulate further research. What makes the subject all the more exciting is that it is beginning to enter the stage at which actual experiments can be contemplated, and some of the articles appearing in this issue discuss some of these exciting new developments. The subject of RQI pulls together concepts and ideas from

  8. 量子点标记的斑点免疫渗滤分析定量检测cTnI%Dot Immunofiltration Assay for Quantitative Detecting cTnI Using Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    范佳; 宋健; 毕丽荣; 周广宇; 张皓; 魏景艳; 杨柏

    2009-01-01

    Quantum dots have physical and optical properties that make them useful tools for high-resolution labeling immunoassay. In this work, a rapid and simple method of quantitative immunoassay for Cardiac tropo-nin I(cTnI) was developed with quantum dots-labeled antibodies. The monoclonal antibodies of cTnI(2F11) could be labeled with CdTe quantum dots and the coupled product (CdTe-2F11) were characterized by SDS-PAGE. The result of immunofiltration assay indicats that the CdTe-2Fl 1 maintains the antibody activity. The cTnI at the different concentrations in NC membrane could react with CdTe-2F11 and be detected with ImageMaster to analyze the fluorescence intensity of the immunodotting. The results show that the detection limit of cTnI is 120 ng, and there is a good linear relation between concentration of cTnI and the fluorescence intensity(R~2 =0.9966).%利用量子点良好的光谱特征和光化学稳定性, 结合免疫分析技术, 对心肌肌钙蛋白I(cTnI)特异性进行定量检测. 用量子点标记cTnI的单克隆抗体(2F11), 通过SDS-PAGE电泳证明标记成功. 斑点免疫膜渗滤法证明标记后的2F11仍具有良好的生物学活性, 再将标记并纯化后的2F11与NC膜上不同浓度的cTnI进行免疫反应, 使用ImageMaster图像分析软件对膜上荧光斑点图像进行定量分析. 应用此方法测得cTnI的浓度和斑点处相对荧光值有良好的线性关系(R~2=0.9966), 最低检出值为120 ng.

  9. Quantum Chaos and Statistical Mechanics

    OpenAIRE

    Srednicki, Mark

    1994-01-01

    We briefly review the well known connection between classical chaos and classical statistical mechanics, and the recently discovered connection between quantum chaos and quantum statistical mechanics.

  10. Quantum criticality from Fisher information

    Science.gov (United States)

    Song, Hongting; Luo, Shunlong; Fu, Shuangshuang

    2017-04-01

    Quantum phase transition is primarily characterized by a qualitative sudden change in the ground state of a quantum system when an external or internal parameter of the Hamiltonian is continuously varied. Investigating quantum criticality using information-theoretic methods has generated fruitful results. Quantum correlations and fidelity have been exploited to characterize the quantum critical phenomena. In this work, we employ quantum Fisher information to study quantum criticality. The singular or extremal point of the quantum Fisher information is adopted as the estimated thermal critical point. By a significant model constructed in Quan et al. (Phys Rev Lett 96: 140604, 2006), the effectiveness of this method is illustrated explicitly.

  11. Problems and solutions in quantum computing and quantum information

    CERN Document Server

    Steeb, Willi-Hans

    2012-01-01

    Quantum computing and quantum information are two of the fastest growing and most exciting research fields in physics. Entanglement, teleportation and the possibility of using the non-local behavior of quantum mechanics to factor integers in random polynomial time have also added to this new interest. This book supplies a huge collection of problems in quantum computing and quantum information together with their detailed solutions, which will prove to be invaluable to students as well as researchers in these fields. All the important concepts and topics such as quantum gates and quantum circuits, product Hilbert spaces, entanglement and entanglement measures, deportation, Bell states, Bell inequality, Schmidt decomposition, quantum Fourier transform, magic gate, von Neumann entropy, quantum cryptography, quantum error corrections, number states and Bose operators, coherent states, squeezed states, Gaussian states, POVM measurement, quantum optics networks, beam splitter, phase shifter and Kerr Hamilton opera...

  12. Quantum teleportation between remote atomic-ensemble quantum memories

    CERN Document Server

    Bao, Xiao-Hui; Li, Che-Ming; Yuan, Zhen-Sheng; Lu, Chao-Yang; Pan, Jian-Wei

    2012-01-01

    Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a "quantum channel", quantum teleportation provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of 100 million rubidium atoms and connected by a 150-meter optical fiber. The spinwave state of one atomic ensemble is mapped to a propagating photon, and subjected to Bell-state measurements with another single photon that is entangled with the spinwave state of the other ensemble. Two-photon detection events herald the succe...

  13. Quantum cluster algebras and quantum nilpotent algebras

    Science.gov (United States)

    Goodearl, Kenneth R.; Yakimov, Milen T.

    2014-01-01

    A major direction in the theory of cluster algebras is to construct (quantum) cluster algebra structures on the (quantized) coordinate rings of various families of varieties arising in Lie theory. We prove that all algebras in a very large axiomatically defined class of noncommutative algebras possess canonical quantum cluster algebra structures. Furthermore, they coincide with the corresponding upper quantum cluster algebras. We also establish analogs of these results for a large class of Poisson nilpotent algebras. Many important families of coordinate rings are subsumed in the class we are covering, which leads to a broad range of applications of the general results to the above-mentioned types of problems. As a consequence, we prove the Berenstein–Zelevinsky conjecture [Berenstein A, Zelevinsky A (2005) Adv Math 195:405–455] for the quantized coordinate rings of double Bruhat cells and construct quantum cluster algebra structures on all quantum unipotent groups, extending the theorem of Geiß et al. [Geiß C, et al. (2013) Selecta Math 19:337–397] for the case of symmetric Kac–Moody groups. Moreover, we prove that the upper cluster algebras of Berenstein et al. [Berenstein A, et al. (2005) Duke Math J 126:1–52] associated with double Bruhat cells coincide with the corresponding cluster algebras. PMID:24982197

  14. Quantum Permanents and Hafnians via Pfaffians

    Science.gov (United States)

    Jing, Naihuan; Zhang, Jian

    2016-10-01

    Quantum determinants and Pfaffians or permanents and Hafnians are introduced on the two-parameter quantum general linear group. Fundamental identities among quantum Pf, Hf, and det are proved in the general setting. We show that there are two special quantum algebras among the quantum groups, where the quantum Pfaffians have integral Laurent polynomials as coefficients. As a consequence, the quantum Hafnian is computed by a closely related quantum permanent and identical to the quantum Pfaffian on this special quantum algebra.

  15. Active quantum walks: a framework for quantum walks with adiabatic quantum evolution

    Science.gov (United States)

    Wu, Nan; Song, Fangmin; Li, Xiangdong

    2016-05-01

    We study a new methodology for quantum walk based algorithms. Different from the passive quantum walk, in which a walker is guided by a quantum walk procedure, the new framework that we developed allows the walker to move by an adiabatic procedure of quantum evolution, as an active way. The use of this active quantum walk is helpful to develop new quantum walk based searching and optimization algorithms.

  16. On Quantum Conditional Probability

    Directory of Open Access Journals (Sweden)

    Isabel Guerra Bobo

    2013-02-01

    Full Text Available We argue that quantum theory does not allow for a generalization of the notion of classical conditional probability by showing that the probability defined by the Lüders rule, standardly interpreted in the literature as the quantum-mechanical conditionalization rule, cannot be interpreted as such.

  17. Towards relativistic quantum geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ridao, Luis Santiago [Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina); Bellini, Mauricio, E-mail: mbellini@mdp.edu.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata (Argentina)

    2015-12-17

    We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner–Nordström black-hole is studied.

  18. Controllability of Quantum Systems

    CERN Document Server

    Schirmer, S G; Solomon, A I

    2003-01-01

    An overview and synthesis of results and criteria for open-loop controllability of Hamiltonian quantum systems obtained using Lie group and Lie algebra techniques is presented. Negative results for open-loop controllability of dissipative systems are discussed, and the superiority of closed-loop (feedback) control for quantum systems is established.

  19. Quantum Dots: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Vukmirovic, Nenad; Wang, Lin-Wang

    2009-11-10

    This review covers the description of the methodologies typically used for the calculation of the electronic structure of self-assembled and colloidal quantum dots. These are illustrated by the results of their application to a selected set of physical effects in quantum dots.

  20. Quantum reverse hypercontractivity

    Energy Technology Data Exchange (ETDEWEB)

    Cubitt, Toby [Department of Computer Science, University College London, London, United Kingdom and Centre for Quantum Information and Foundations, DAMTP, University of Cambridge, Cambridge (United Kingdom); Kastoryano, Michael [NBIA, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Montanaro, Ashley [School of Mathematics, University of Bristol, Bristol (United Kingdom); Temme, Kristan [Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-10-15

    We develop reverse versions of hypercontractive inequalities for quantum channels. By generalizing classical techniques, we prove a reverse hypercontractive inequality for tensor products of qubit depolarizing channels. We apply this to obtain a rapid mixing result for depolarizing noise applied to large subspaces and to prove bounds on a quantum generalization of non-interactive correlation distillation.