0+ and 1+ heavy mesons in heavy chiral unitary approach
In terms of the heavy chiral unitary approach, the Ds0*(2317), Ds1*(2460) and D0*(2308) resonances are discussed within the molecular state model. By examining the poles of the full unitary coupled-channel scattering amplitude on appropriate Riemann sheets, the former two states can be well reproduced, but not the third state. If one believes that the third state and first state are corresponding states in the non-strange and strange sectors, respectively, and they are all dominated by the molecular structure, there should exist one wide-width state at about 2.1 GeV and one narrow-width state at about 2.44 GeV, which are associated with the D0*(2308) state. Meanwhile, we predict possible B0*(5536) [B1*(5581)] and B0*(5819) [B1*(5877)] states in the non-strange sector as the corresponding states of the strange Bs0*(5725) [Bs1*(5778)] ones
eta, eta-prime --> pi+ pi- l+ l- in a chiral unitary approach
Borasoy, B
2007-01-01
The decays eta, eta-prime --> pi+ pi- l+ l- with l = e, mu are investigated within a chiral unitary approach which combines the chiral effective Lagrangian with a coupled-channels Bethe-Salpeter equation. Predictions for the decay widths and spectra are given.
The $\\Xi^* \\bar{K}$ and $\\Omega \\eta$ interaction within a chiral unitary approach
Xu, Siqi; Chen, Xurong; Jia, Duojie
2015-01-01
In this work we study the interaction of the coupled channels $\\Omega \\eta$ and $\\Xi^* \\bar{K}$ within the chiral unitary approach. The systems under consideration have total isospins $0$, strangeness $S = -3$, and spin $3/2$. We studied the $s$ wave interaction which implies that the possible resonances generated in the system can have spin-parity $J^P = 3/2^-$. The unitary amplitudes in coupled channels develop poles that can be associated with some known baryonic resonances. We find there is a dynamically generated $3/2^-$ $\\Omega$ state with mass around $1800$ MeV, which is in agreement with the predictions of the five-quark model.
The phi --> pi^+ pi^- and phi radiative decays within a chiral unitary approach
Oset, E.; Hirenzaki, S.; Marco, E.; Oller, J. A.; Pelaez, J.R.(Dept. Física Teórica II., Universidad Complutense, Madrid, 28040, Spain); Toki, H.
2000-01-01
We report on recent results on the decay of the phi into pi^+ pi^- and phi radiative decays into pi^0 pi^0 gamma and pi^0 eta gamma, which require the consideration of the final state interaction of a pair of mesons in a region inaccessible to Chiral Perturbation Theory. By using nonperturbative chiral unitary methods for the meson meson interaction we can obtain the corresponding decay widths and the results are compared with recent experimental data.
Chiral unitary theory: Application to nuclear problems
E Oset; D Cabrera; H C Chiang; C Garcia Recio; S Hirenzaki; S S Kamalov; J Nieves; Y Okumura; A Ramos; H Toki; M J Vicente Vacas
2001-08-01
In this talk we brieﬂy describe some basic elements of chiral perturbation theory, , and how the implementation of unitarity and other novel elements lead to a better expansion of the -matrix for meson–meson and meson–baryon interactions. Applications are then done to the interaction in nuclear matter in the scalar and vector channels, antikaons in nuclei and - atoms, and how the meson properties are changed in a nuclear medium.
Chiral dynamics in U(3) unitary chiral perturbation theory
We perform a complete one-loop calculation of meson-meson scattering, and of the scalar and pseudoscalar form factors in U(3) chiral perturbation theory with the inclusion of explicit resonance fields. This effective field theory takes into account the low-energy effects of the QCD UA(1) anomaly explicitly in the dynamics. The calculations are supplied by non-perturbative unitarization techniques that provide the final results for the meson-meson scattering partial waves and the scalar form factors considered. We present thorough analyses on the scattering data, resonance spectroscopy, spectral functions, Weinberg-like sum rules and semi-local duality. The last two requirements establish relations between the scalar spectrum with the pseudoscalar and vector ones, respectively. The NC extrapolation of the various quantities is studied as well. The fulfillment of all these non-trivial aspects of the QCD dynamics by our results gives a strong support to the emerging picture for the scalar dynamics and its related spectrum.
On the Isomorphic Description of Chiral Symmetry Breaking by Non-Unitary Lie Groups
Bietenholz, Wolfgang
2009-01-01
It is well-known that chiral symmetry breaking ($\\chi$SB) in QCD with $N_{f}=2$ light quark flavours can be described by orthogonal groups as $O(4) \\to O(3)$, due to local isomorphisms. Here we discuss the question how specific this property is. We consider generalised forms of $\\chi$SB involving an arbitrary number of light flavours of continuum or lattice fermions, in various representations. We search systematically for isomorphic descriptions by non-unitary, compact Lie groups. It turns o...
We derive the leading two-pion-exchange contributions to the two-nucleon electromagnetic current operator in the framework of chiral effective field theory using the method of unitary transformation. Explicit results for the current and charge densities are given in momentum and coordinate space.
On the Isomorphic Description of Chiral Symmetry Breaking by Non-Unitary Lie Groups
Bietenholz, Wolfgang
2009-01-01
It is well-known that chiral symmetry breaking ($\\chi$SB) in QCD with $N_{f}=2$ light quark flavours can be described by orthogonal groups as $O(4) \\to O(3)$, due to local isomorphisms. Here we discuss the question how specific this property is. We consider generalised forms of $\\chi$SB involving an arbitrary number of light flavours of continuum or lattice fermions, in various representations. We search systematically for isomorphic descriptions by non-unitary, compact Lie groups. It turns out that there are a few alternative options in terms of orthogonal groups, while we did not find any description entirely based on symplectic or exceptional Lie groups. If we adapt such an alternative as the symmetry breaking pattern for a generalised Higgs mechanism, we may consider a Higgs particle composed of bound fermions and trace back the mass generation to $\\chi$SB. In fact, some of the patterns that we encounter appear in technicolour models. In particular if one observes a Higgs mechanism that can be expressed i...
An Informal Overview of the Unitary Group Approach
Sonnad, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kruse, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Baker, R. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy
2016-06-13
The Unitary Groups Approach (UGA) is an elegant and conceptually unified approach to quantum structure calculations. It has been widely used in molecular structure calculations, and holds the promise of a single computational approach to structure calculations in a variety of different fields. We explore the possibility of extending the UGA to computations in atomic and nuclear structure as a simpler alternative to traditional Racah algebra-based approaches. We provide a simple introduction to the basic UGA and consider some of the issues in using the UGA with spin-dependent, multi-body Hamiltonians requiring multi-shell bases adapted to additional symmetries. While the UGA is perfectly capable of dealing with such problems, it is seen that the complexity rises dramatically, and the UGA is not at this time, a simpler alternative to Racah algebra-based approaches.
An Informal Overview of the Unitary Group Approach
Sonnad, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kruse, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Baker, R. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy
2016-06-13
The Unitary Groups Approach (UGA) is an elegant and conceptually unified approach to quantum structure calculations. It has been widely used in molecular structure calculations, and holds the promise of a single computational approach to structure calculations in a variety of different fields. We explore the possibility of extending the UGA to computations in atomic and nuclear structure as a simpler alternative to traditional Racah algebra based approaches. We provide a simple introduction to the basic UGA and consider some of the issues in using the UGA with spin dependent, multi-body Hamiltonians requiring multi-shell bases adapted to additional symmetries. While the UGA is perfectly capable of dealing with such problems, it is seen that the complexity rises dramatically, and the UGA is not at this time, a simpler alternative to Racah algebra based approaches.
Highlights: •We theoretically study an impurity scattering effect on the vortex core structure in a chiral p-wave superconductor. •A low-temperature vortex core shrinkage (or Kramer–Pesch effect) is investigated. •The robustness of the Kramer–Pesch effect against an impurity scattering in the Born limit is lost in the unitary limit. -- Abstract: We theoretically investigate a non-magnetic impurity effect on the temperature dependence of the vortex core shrinkage (Kramer–Pesch effect) in a chiral p-wave superconductor. The Born limit and the unitary limit scattering are compared within the framework of the quasiclassical theory of superconductivity. We find that the robustness of the Kramer–Pesch effect against the impurity scattering in the Born limit is lost in the unitary limit
Hayashi, Nobuhiko, E-mail: n-hayashi@21c.osakafu-u.ac.jp [NanoSquare Research Center (N2RC), Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai 599-8570 (Japan); Kurosawa, Noriyuki [Department of Basic Science, University of Tokyo, Komaba, Meguro, Tokyo 153-8902 (Japan); Arahata, Emiko [Institute of Industrial Science, University of Tokyo, Komaba, Meguro, Tokyo 153-8505 (Japan); Kato, Yusuke [Department of Basic Science, University of Tokyo, Komaba, Meguro, Tokyo 153-8902 (Japan); Tanuma, Yasunari [Faculty of Engineering and Resource Science, Akita University, Akita 010-8502 (Japan); Tanaka, Yukio [Department of Applied Physics, Nagoya University, Nagoya 464-8603 (Japan); Golubov, Alexander A. [Faculty of Science and Technology and MESA Institute for Nanotechnology, University of Twente, 7500 AE Enshede (Netherlands)
2013-11-15
Highlights: •We theoretically study an impurity scattering effect on the vortex core structure in a chiral p-wave superconductor. •A low-temperature vortex core shrinkage (or Kramer–Pesch effect) is investigated. •The robustness of the Kramer–Pesch effect against an impurity scattering in the Born limit is lost in the unitary limit. -- Abstract: We theoretically investigate a non-magnetic impurity effect on the temperature dependence of the vortex core shrinkage (Kramer–Pesch effect) in a chiral p-wave superconductor. The Born limit and the unitary limit scattering are compared within the framework of the quasiclassical theory of superconductivity. We find that the robustness of the Kramer–Pesch effect against the impurity scattering in the Born limit is lost in the unitary limit.
Chiral Symmetry in algebraic and analytic approaches
Vereshagin, V.; Dillig, M.; Vereshagin, A.
1996-01-01
We compare among themselves two different methods for the derivation of results following from the requirement of polynomial boundedness of tree-level chiral amplitudes. It is shown that the results of the algebraic approach are valid also in the framework of the analytical one. This means that the system of Sum Rules and Bootstrap equations previously obtained with the help of the latter approach can be analyzed in terms of reducible representations of the unbroken Chiral group with the know...
Superspace Unitary Operator for Some Interesting Abelian Models: Superfield Approach
Bhanja, T; Malik, R P
2015-01-01
Within the framework of augmented version of superfield formalism, we choose the superspace unitary operator and show its usefulness in the derivation of Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations for a set of interesting models for the Abelian 1-form gauge theory. These models are (i) a one (0+1)-dimensional (1D) toy model of a rigid rotor, (ii) the two (1+1)-dimensional (2D) modified versions of the Proca and anomalous Abelian 1-form gauge theories, and (iii) the 2D self-dual bosonic field theory. We provide, in some sense, the alternatives to the horizontality condition (HC) and the gauge invariant restrictions (GIRs) in the language of the above superspace (SUSP) unitary operator. One of the key observations of our present endeavor is the result that the SUSP unitary operator and its hermitian conjugate are found to be the same for all the Abelian models under consideration (including the interacting Abelian 1-form gauge theories with Dirac and complex scalar fields which have...
The chiral magnetic effect in hydrodynamical approach
Sadofyev, A. V.; Isachenkov, M. V.
2010-01-01
In quark-gluon plasma nonzero chirality can be induced by the chiral anomaly. When a magnetic field is applied to a system with nonzero chirality an electromagnetic current is induced along the magnetic field. This phenomenon is called the chiral magnetic effect. In this paper appearance of the chiral magnetic effect in hydrodynamical approximation is shown. We consider a hydrodynamical model for chiral liquid with two independent currents of left and right handed particles in the presence of...
Matrix element evaluation in the unitary group approach to the electron correlation problem
Computationally effective formulations are presented for the evaluation of matrix elements of unitary group generators and products of generators between Gelfand states. These matrix elements are the coefficients of the orbital integrals in the expressions for the Hamiltonian matrix elements in the Gelfand basis, and as such are the key elements in any application of the unitary group approach to wave-function calculations. The present formulations, which, like previous analyses, result in a simple factorization of the generator matrix elements, are based on a graphical representation of the Gelfand basis, and do not require orbital permutations or an interpretation of the Gelfand states in terms of Young tableaus. It is shown that the resulting formalism can lead to very efficient procedures for direct configuration-interaction calculations, and probably also for perturbation-theory treatments. 15 references
A phenomenological approach to the equation of state of a unitary Fermi gas
M V N Murthy; M Brack; R K Bhaduri
2014-06-01
We propose a phenomenological approach for the equation of state of a unitary Fermi gas. The universal equation of state is parametrized in terms of Fermi–Dirac integrals. This reproduces the experimental data over the accessible range of fugacity and normalized temperature, but cannot describe the superfluid phase transition found in the MIT experiment [Ku et al, Science 335, 563 (2012)]. The most sensitive data for compressibility and specific heat at phase transition can, however, be fitted by introducing into the grand partition function a pair of complex conjugate zeros lying in the complex fugacity plane slightly off the real axis.
无
2006-01-01
The equivalence of multipartite quantum mixed states under local unitary transformations is studied. A criterion for the equivalence of non-degenerate mixed multipartite quantum states under local unitary transformationsis presented.
A new approach to chiral fermions on the lattice
We wish to describe a method for formulating, on the lattice, field theories that contain Dirac particles with chiral couplings to gauge fields. As is well-known, the most straight-forward lattice transcription of the continuum action for a Dirac particle leads to the doubling problem: for every particle of a given chirality in the continuum theory, there appear on the lattice, in d dimensions, 2d particles, with equal numbers of particles of left- and right-handed chirality. No-go theorems, state that it is impossible to eliminate the doubling problem and still maintain an exact chiral gauge symmetry. Rather than follow an approach that attempts to circumvent the no-go theorems we, instead, explore the possibility of abandoning exact chiral symmetry
Statistical Mechanical Approach to the Equation of State of Unitary Fermi Gases
De Silva, Theja N
2016-01-01
We combine a Tan's universal relation with a basic statistical mechanical approach to derive a general equation of state for unitary Fermi gases. The universal equation of state is written as a series solution to a self consistent integral equation where the general solution is a linear combination of Fermi functions. By truncating our series solution to four terms with already known exact theoretical inputs at limiting cases, namely the first three virial coefficients and the Bertsch parameter, we find a good agreement with experimental measurements in the entire temperature region in the normal state. Our analytical equation of state agrees with experimental data up to the fugacity $z = 18$, which is a vast improvement over the other analytical equations of state available where the agreements is \\emph{only} up to $z \\approx 7$.
Eliminating the chiral anomaly via symplectic embedding approach
Mendes, A C R; Oliveira, W
2009-01-01
The quantization of the chiral Schwinger model $(\\chi QED_{2})$ with one-parameter class Faddeevian regularization is hampered by the chiral anomaly, i.e., the Gauss law commutator exhibits Faddeev's anomaly. To overcome this kind of problem, we propose to eliminate this anomaly by embedding the theory through a new gauge-invariant formalism based on the enlargement of the phase space with the introduction of Wess-Zumino(WZ) fields and the symplectic approach. This process opens up a possibility to formulate different, but dynamically equivalent, gauge invariant versions for the model and also gives a geometrical interpretation to the arbitrariness presents on the BFFT and iterative conversion methods. Further, we observe that the elimination of the chiral anomaly imposes a condition on the chiral parameters present on the original model and on the WZ sector.
Supersymmetric Unitary Operator in QED with Dirac and Complex Scalar Fields: Superfield Approach
Shukla, D; Malik, R P
2015-01-01
We exploit the strength of supersymmetric (SUSY) unitary operator to obtain the results of the application of horizontality condition (HC) within the framework of augmented version of superfield formalism that is applied to the interacting systems of Abelian 1-form gauge theories where U(1) Abelian 1-form gauge field couples to the Dirac and complex scalar fields in the physical four (3 + 1)-dimensions of spacetime. These interacting theories are generalized onto a (4, 2)-dimensional supermanifold that is parametrized by the four (3 + 1)-dimensional (4D) spacetime variable and a pair of Grassmannian variables. To derive the (anti-)BRST symmetries for the matter fields, we impose the gauge invariant restrictions (GIRs) on the superfields defined on the (4, 2)-dimensional supermanifold. We discuss various outcomes that emerge from our knowledge of the SUSY unitary operator.
Takayama, Takahiro; Mochizuki, Toshiki; Todoroki, Kenichiro; Min, Jun Zhe; Mizuno, Hajime; Inoue, Koichi; Akatsu, Hiroyasu; Noge, Ichiro; Toyo'oka, Toshimasa
2015-10-22
Chiral metabolites are found in a wide variety of living organisms and some of them are understood to be physiologically active compounds and biomarkers. However, the overall analysis of chiral metabolomics is quite difficult due to the high number of metabolites, the significant diversity in their physicochemical properties, and concentration range from metabolite-to-metabolite. To solve this difficulty, we developed a novel approach for chiral metabolomics fingerprinting and chiral metabolomics extraction, which is based on the labeling of a pair of enantiomers of chiral derivatization reagents (i.e., DMT-(S,R)-Pro-OSu and DMT-3(S,R)-Apy) and precursor ion scan chromatography of the derivatives. The multivariate statistics is also required for this strategy. The proposed procedures were evaluated by the detection of a diagnostic marker (i.e., d-lactic acid) using the saliva of diabetic patients. This method was used for the determination of biomarker candidates of chiral amines and carboxyls in Alzheimer's disease (AD) brain homogenates. As the results, l-phenylalanine (L-Phe) and l-lactic acid (L-LA) were identified as the decreased and increased biomarker candidates in the AD brain, respectively. Therefore, the proposed approach seems to be helpful for the determination of non-target chiral metabolomics possessing amines and carboxyls. PMID:26526912
Matrix elements of unitary group generators between spin-adapted antisymmetric states are shown to be proportional to spin matrix elements of so-called line-up permutations. The proportionality factor is given explicitly as a simple function of the orbital occupation numbers. If one bases the theory on ordered orbital products, the line-up permutations are given a priori. The final formulas have a very simple structure; this property is a direct consequence of the fact that the spin functions have been taken to be geminally antisymmetric. 1 table
Antikaon induced Ξ production from a chiral model at NLO
Feijoo A.
2014-01-01
Full Text Available We study the meson-baryon interaction in the strangeness S = −1 sector using a chiral unitary approach, paying particular attention to the K̄N → KΞ reaction, especially important for constraining the next-to-leading order chiral terms, and considering also the effect of high spin hyperonic resonances. We also present results for the production of Ξ hyperons in nuclei
Davood Mousanezhad
2016-03-01
Full Text Available The effects of two geometric refinement strategies widespread in natural structures, chirality and self-similar hierarchy, on the in-plane elastic response of two-dimensional honeycombs were studied systematically. Simple closed-form expressions were derived for the elastic moduli of several chiral, anti-chiral, and hierarchical honeycombs with hexagon and square based networks. Finite element analysis was employed to validate the analytical estimates of the elastic moduli. The results were also compared with the numerical and experimental data available in the literature. We found that introducing a hierarchical refinement increases the Young’s modulus of hexagon based honeycombs while decreases their shear modulus. For square based honeycombs, hierarchy increases the shear modulus while decreasing their Young’s modulus. Introducing chirality was shown to always decrease the Young’s modulus and Poisson’s ratio of the structure. However, chirality remains the only route to auxeticity. In particular, we found that anti-tetra-chiral structures were capable of simultaneously exhibiting anisotropy, auxeticity, and remarkably low shear modulus as the magnitude of the chirality of the unit cell increases.
Heidbreder, Rebeca
2015-12-01
The aim of this paper is to build a case for the utility of conceptualizing ADHD, not as a unitary disorder that contains several subtypes, but rather as a marker of impairment in attention and/or impulsivity that can be used to identify one of several disorders belonging to a spectrum. The literature will be reviewed to provide an overview of what is known about ADHD in terms of heterogeneity in symptomatology, neuropsychology, neurobiology, as well as comorbidity with other diseases and treatment options. The data from these areas of research will be critically analyzed to support the construct of a spectrum of disorders that can capture the great variability that exists between individuals with ADHD and can discriminate between separate disorders that manifest similar symptoms. The symptoms associated with ADHD can be viewed as dimensional markers that point to a spectrum of related disorders that have as part of their characteristics impairments of attention and impulsivity. The spectrum can accommodate symmetrically and asymmetrically comorbid psychiatric disorders associated with ADHD as well as the wide heterogeneity known to be a part of the ADHD disorder. Individuals presenting with impairments associated with ADHD should be treated as having a positive marker for a spectrum disorder that has as part of its characteristics impairments of attention and/or impulsivity. The identification of impairment in attention and/or impulsivity should be a starting point for further testing rather than being an endpoint of diagnosis that results in pharmacological treatment that may or may not be the optimal therapy. Rather than continuing to attribute a large amount of heterogeneity in symptom presentation as well as a high degree of symmetric and asymmetric comorbidity to a single disorder, clinical evaluation should turn to the diagnosis of the type of attentional deficit and/or impulsivity an individual has in order to colocate the individual's disorder on a
An analytical approach for treating unitary quantum systems with initial mixed states
Mixed states are important in quantum optics since they frequently appear in decoherence problems. When one of the components of the system is initially prepared in a mixed state and the mathematical closed form of the evolution operator of the system is not available, one cannot deduce the density matrix. We present an analytical approach to accurately solve this problem. We exploit the fact that any mixed state can be expressed in terms of the phase state. The approach can be applied on the condition that Schrödinger’s equation of the system is solvable for any arbitrary initial state. We verify the validity of the approach for two examples, namely, the Jaynes–Cummings model and the two-qubit problem. Our results are in good agreement with the available results in the literature. This approach opens new perspectives for treating complicated systems and may impact other applications in quantum theory. (paper)
Chiral and deconfinement phase transition in the Hamiltonian approach to QCD in Coulomb gauge
Reinhardt, H
2016-01-01
The chiral and deconfinement phase transitions are investigated within the variational Hamiltonian approach to QCD in Coulomb gauge. The temperature $\\beta^{-1}$ is introduced by compactifying a spatial dimension. Thereby the whole temperature dependence is encoded in the vacuum state on the spatial manifold $\\mathbb{R}^2 \\times S^1(\\beta)$. The chiral quark condensate and the dual quark condensate (dressed Polyakov loop) are calculated as function of the temperature. From their inflection points the pseudo-critical temperatures for the chiral and deconfinement crossover transitions are determined. Using the zero-temperature quark and gluon propagators obtained within the variational approach as input, we find 226 MeV and 262 MeV, respectively, for the chiral and deconfinement transition.
The Graphical Unitary Group Approach (GUGA) was cast into an extraordinarily powerful form by restructuring the Hamiltonian in terms of loop types. This restructuring allows the adoption of the loop-driven formulation which illuminates vast numbers of previously unappreciated relationships between otherwise distinct Hamiltonian matrix elements. The theoretical/methodological contributions made here include the development of the loop-driven formula generation algorithm, a solution of the upper walk problem used to develop a loop breakdown algorithm, the restriction of configuration space employed to the multireference interacting space, and the restructuring of the Hamiltonian in terms of loop types. Several other developments are presented and discussed. Among these developments are the use of new segment coefficients, improvements in the loop-driven algorithm, implicit generation of loops wholly within the external space adapted within the framework of the loop-driven methodology, and comparisons of the diagonalization tape method to the direct method. It is also shown how it is possible to implement the GUGA method without the time-consuming full (m5) four-index transformation. A particularly promising new direction presented here involves the use of the GUGA methodology to obtain one-electron and two-electron density matrices. Once these are known, analytical gradients (first derivatives) of the CI potential energy are easily obtained. Several test calculations are examined in detail to illustrate the unique features of the method. Also included is a calculation on the asymmetric 21A' state of SO2 with 23,613 configurations to demonstrate methods for the diagonalization of very large matrices on a minicomputer. 6 figures, 6 tables
Approaching the chiral point in two-flavour lattice simulations
We investigate the behaviour of the pion decay constant and the pion mass in two-flavour lattice QCD, with the physical and chiral points as ultimate goal. Measurements come from the ensembles generated by the CLS initiative using the O(a)-improved Wilson formulation, with lattice spacing down to about 0.05 fermi and pion masses as low as 190 MeV. The applicability of SU(2) chiral perturbation theory is investigated, and various functional forms, and their range of validity, are compared. The physical scale is set through the kaon decay constant, whose measurement is enabled by inserting a third, heavier valence strange quark.
The effective action approach applied to nuclear chiral sigma model
The nuclear chiral sigma model of nuclear matter is considered by means of the Cornwall-Jackiw-tomboulis (CTJ) effective action. The method provides a very general framework for investigating many important problems: chiral symmetry in nuclear medium, energy density of nuclear ground state, nuclear Schwinger-Dyson (SD) equations, etc. It is shown that the SD equations for sigma-omega mixing are actually not present in this formalism. For numerical computation purposes the Hartree-Fock (HF) approximation for ground state energy density is also presented. (author). 26 refs
Chiral symmetry in the path-integral approach
The derivation of anomalous Ward-Takahashi identities related to chiral symmetries in the path-integral framework is presented. Some two-dimensional models in both abelian and non-abelian cases are discussed. The quantization of such theories using Weyl fermions is also presented. (L.C.)
A new approach to the chiral separation of novel diazenes
Vojtylová, Terézia; Niezgoda, I.; Galewski, Z.; Hamplová, Věra; Sýkora, D.
2015-01-01
Roč. 38, č. 24 (2015), 4211-4215. ISSN 1615-9306 R&D Projects: GA ČR GA13-14133S Institutional support: RVO:68378271 Keywords : azobenzenes * chiral separation * high-performance liquid chromatography * liquid-crystalline materials * photoinduced isomerization Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.737, year: 2014
Non-chiral fusion rules, structure constants of $D_{m}$ minimal models
Rida, A
1999-01-01
We present a technique to construct, for $D_{m}$ unitary minimal models, the non-chiral fusion rules which determines the operator content of the operator product algebra. Using these rules we solve the bootstrap equations and therefore determine the structure constants of these models. Through this approach we emphasize the role played by some discrete symmetries in the classification of minimal models.
Local Unitary Invariants for Multipartite Quantum Systems
Wang, Jing; Li, Ming; Fei, Shao-Ming; Li-Jost, Xianqing
2014-01-01
We present an approach of constructing invariants under local unitary transformations for multipartite quantum systems. The invariants constructed in this way can be complement to that in [Science 340 (2013) 1205-1208]. Detailed examples are given to compute such invariant in detail. It is shown that these invariants can be used to detect the local unitary equivalence of degenerated quantum states.
Numerical study of chiral plasma instability within the classical statistical field theory approach
Buividovich, P. V.; Ulybyshev, M. V.
2016-07-01
We report on a numerical study of real-time dynamics of electromagnetically interacting chirally imbalanced lattice Dirac fermions within the classical statistical field theory approach. Namely, we perform exact simulations of the real-time quantum evolution of fermionic fields coupled to classical electromagnetic fields, which are in turn coupled to the vacuum expectation value of the fermionic electric current. We use Wilson-Dirac Hamiltonian for fermions, and noncompact action for the gauge field. In general, we observe that the backreaction of fermions on the electromagnetic field prevents the system from acquiring chirality imbalance. In the case of chirality pumping in parallel electric and magnetic fields, the electric field is screened by the produced on-shell fermions and the accumulation of chirality is hence stopped. In the case of evolution with initially present chirality imbalance, axial charge tends to transform to helicity of the electromagnetic field. By performing simulations on large lattices we show that in most cases this decay process is accompanied by the inverse cascade phenomenon, which transfers energy from short-wavelength to long-wavelength electromagnetic fields. In some simulations, however, we observe a very clear signature of inverse cascade for the helical magnetic fields that is not accompanied by the axial charge decay. This suggests that the relation between the inverse cascade and axial charge decay is not as straightforward as predicted by the simplest form of anomalous Maxwell equations.
Chiral-particle Approach to Hadrons in an Extended Chiral ($\\sigma,\\pi,\\omega$) Mean-Field Model
Uechi, Schun T
2010-01-01
The chiral nonlinear ($\\sigma,\\pi,\\omega$) mean-field model is an extension of the conserving nonlinear (nonchiral) $\\sigma$-$\\omega$ hadronic mean-field model which is thermodynamically consistent, relativistic and Lorentz-covariant mean-field theory of hadrons. In the extended chiral ($\\sigma,\\pi,\\omega$) mean-field model, all the masses of hadrons are produced by chiral symmetry breaking mechanism, which is different from other conventional chiral partner models. By comparing both nonchiral and chiral mean-field approximations, the effects of chiral symmetry breaking to the mass of $\\sigma$-meson, coefficients of nonlinear interactions, coupling ratios of hyperons to nucleons and Fermi-liquid properties are investigated in nuclear matter, hyperonic matter, and neutron stars.
In-medium properties of kaons in a chiral approach
The first order self-energy corrections of the kaon in the symmetric nuclear matter are calculated from kaon-nucleon scattering matrix elements using a chiral Lagrangian within the framework of relativistic mean field approximation. It shows that the effective mass and the potential of K+ meson are identical with those of K- meson in the nuclear matter, respectively. The effective mass of the kaon in the nuclear matter decreases with the nuclear density increasing, and is not relevant to the kaon-nucleon Sigma term. The kaon-nucleus potential is positive and increases with the nuclear density. Moreover, the influence of the resonance Λ(1405) on the K--nucleus potential due to the re-scattering term is discussed. Our results indicate the K- meson could not be bound in the nuclei even if the contribution of Λ(1405) resonance is considered. (author)
Approach to Chandrasekhar-Kendall-Woltjer State in a Chiral Plasma
Xia, Xiao-liang; Wang, Qun
2016-01-01
We study the time evolution of the magnetic field in a plasma with a chiral magnetic current. The Vector Spherical Harmonic functions (VSH) are used to expand all fields. We define a measure for the Chandrasekhar-Kendall-Woltjer (CKW) state, which has a simple form in VSH expansion. We propose the conditions for a general class of initial momentum spectra that will evolve into the CKW state. For this class of initial conditions, to approach the CKW state, (i) a non-vanishing chiral magnetic conductivity is necessary, and (ii) the time integration of the product of the electric resistivity and chiral magnetic conductivity must grow faster than the time integration of the resistivity. We give a few examples to test these conditions numerically which work very well.
Approach to synthesis and structure of chiral multi-functionalized organophosphorus derivatives
无
2003-01-01
The diastereomerically pure organophosphorus derivatives containing multiple chiral centers 5 and 5( were obtained, respectively, in 62%-84% yields with ≥98% de (diastereomeric excess) via asymmetric reaction of the chiron, 3-bromo-2(5H)-furanone 4 with racemic diethyl (-hydroxyl- substituted-phosphonates 3+ 3( and further through the separation of the diastereomeric mixture by chromatography. The structures of the chiral organophosphorus derivatives were identified on the basis of their elementary and spectroscopic data, such as IR, 1H NMR,13C NMR, MS and X-ray crystallography. In this report, the synthetic methods ofthe active organophosphorus substrates, the structure characterization and resolution, the optical purity and the stereochemistry of the chiral products were discussed. These results provide a new idea and a good method for synthesizing some natural organophosphorus compounds and approaching their biological activities, also a facile route to the application of organophosphorus substrates.
Cooper, F. [Los Alamos National Labs., NM (United States)
1997-09-22
This paper contains viewgraphs on unusual dileptons at Brookhaven RHIC. A field theory approach is used based on a non-equilibrium chiral phase transformation utilizing the schroedinger and Heisenberg picture.
Héctor Torres-Silva
2008-11-01
Full Text Available In this paper we show that a new approach leads to Maxwell's and Podolsky's electrodynamics, provided we start from chiral constitutive relations instead of the usual Coulomb's law.En este trabajo se muestra que un nuevo esquema conduce a la electrodinámica de Maxwell y a la electrodinámica de Podolsky, partiendo con relaciones constitutivas quirales en lugar de la usual ley de Coulomb.
New tests of the gauge-fixing approach to lattice chiral gauge theories
We report on recent progress with the gauge-fixing approach to lattice chiral gauge theories. The bosonic sector of the gauge-fixing approach is studied with fully dynamical U(1) gauge fields. We demonstrate that it is important to formulate the Lorentz gauge-fixing action such that the dense set of lattice Gribov copies is removed, and the gauge-fixing action has a unique absolute minimum. We then show that the spectrum in the continuum limit contains only the desired massless photon, as expected
Hamiltonian Simulation Using Linear Combinations of Unitary Operations
Childs, Andrew M.; Wiebe, Nathan
2012-01-01
We present a new approach to simulating Hamiltonian dynamics based on implementing linear combinations of unitary operations rather than products of unitary operations. The resulting algorithm has superior performance to existing simulation algorithms based on product formulas and, most notably, scales better with the simulation error than any known Hamiltonian simulation technique. Our main tool is a general method to nearly deterministically implement linear combinations of nearby unitary o...
A multiscale approach for estimating the chirality effects in carbon nanotube reinforced composites
Joshi, Unnati A.; Sharma, Satish C.; Harsha, S. P.
2012-08-01
In this paper, the multiscale representative volume element approach is proposed for modeling the elastic behavior of carbon nanotubes reinforced composites. The representative volume element incorporates the continuum approach, while carbon nanotube characterizes the atomistic approach. Space frame structure similar to three dimensional beams and point masses are employed to simulate the discrete geometrical constitution of the single walled carbon nanotube. The covalent bonds between carbon atoms found in the hexagonal lattices are assigned elastic properties using beam elements. The point masses applied on each node are coinciding with the carbon atoms work as mass of beam elements. The matrix phase is modeled as a continuum medium using solid elements. These two regions are interconnected by interfacial zone using beam elements. Analysis of nanocomposites having single walled carbon nanotube with different chiralities is performed, using an atomistic finite element model based on a molecular structural mechanics approach. Using the proposed multi scale model, the deformations obtained from the simulations are used to predict the elastic and shear moduli of the nanocomposites. A significant enhancement in the stiffness of the nanocomposites is observed. The effects of interfacial shear strength, stiffness, tensile strength, chirality, length of carbon nanotube, material of matrix, types of representative volume elements and types of loading conditions on the mechanical behavior of the nanocomposites are estimated. The finite element results are compared with the rule of mixtures using formulae. It is found that the results offered by proposed model, are in close proximity with those obtained by the rule of mixtures.
Generalized Ginzburg–Landau approach to inhomogeneous phases in nonlocal chiral quark models
We analyze the presence of inhomogeneous phases in the QCD phase diagram within the framework of nonlocal chiral quark models. We concentrate in particular in the positions of the tricritical (TCP) and Lifshitz (LP) points, which are studied in a general context using a generalized Ginzburg–Landau approach. We find that for all the phenomenologically acceptable model parametrizations considered the TCP is located at a higher temperature and a lower chemical potential in comparison with the LP. Consequently, these models seem to favor a scenario in which the onset of the first order transition between homogeneous phases is not covered by an inhomogeneous, energetically favored phase
Analytic derivatives of the potential energy for Self-Consistent-Field (SCF) wave functions have been developed in recent years and found to be useful tools. The first derivative for configuration interaction (CI) wave functions is also available. This work details the extension of analytic methods to energy second derivatives for CI wave functions. The principal extension required for second derivatives is evaluation of the first order change in the CI wave function with respect to a nuclear perturbation. The shape driven graphical unitary group approach (SDGUGA) direct CI program was adapted to evaluate this term via the coupled-perturbed CI equations. Several iterative schemes are compared for use in solving these equations. The pilot program makes no use of molecular symmetry but the timing results show that utilization of molecular symmetry is desirable. The principles for defining and solving a set of symmetry adapted equations are discussed. Evaluation of the second derivative also requires the solution of the second order coupled-perturbed Hartree-Fock equations to obtain the correction to the molecular orbitals due to the nuclear perturbation. This process takes a consistently higher percentage of the computation time than for the first order equations alone and a strategy for its reduction is discussed
Entanglement quantification by local unitaries
Monras, A; Giampaolo, S M; Gualdi, G; Davies, G B; Illuminati, F
2011-01-01
Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitaries play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as "shield entanglement". They are constructed by first considering the (squared) Hilbert- Schmidt distance of the state from the set of states obtained by applying to it a given local unitary. To the action of each different local unitary there corresponds a different distance. We then minimize these distances over the sets of local unitaries with different spectra, obtaining an entire family of different entanglement monotones. We show that these shield entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary f...
Black holes, quantum information, and unitary evolution
Giddings, Steven B
2012-01-01
The unitary crisis for black holes indicates an apparent need to modify local quantum field theory. This paper explores the idea that quantum mechanics and in particular unitarity are fundamental principles, but at the price of familiar locality. Thus, one should seek to parameterize unitary evolution, extending the field theory description of black holes, such that their quantum information is transferred to the external state. This discussion is set in a broader framework of unitary evolution acting on Hilbert spaces comprising subsystems. Here, various constraints can be placed on the dynamics, based on quantum information-theoretic and other general physical considerations, and one can seek to describe dynamics with "minimal" departure from field theory. While usual spacetime locality may not be a precise concept in quantum gravity, approximate locality seems an important ingredient in physics. In such a Hilbert space approach an apparently "coarser" form of localization can be described in terms of tenso...
Gómez-Rocha, María
2012-01-01
In this article we point out that the unitary transformation that relates the chiral basis $\\{R; I J^{PC}\\}$ and the $\\{I; ^{2S+1}L_J \\}$ basis, which was already derived for canonical spin in instant form, is also applicable in light-cone representations. From the most general expression for the Clebsch-Gordan coefficients of the Poincar\\'e group one can see that the chiral limit brings the angular momentum coupling into a simple form that permits a clear relation in terms of SU(2) Clebsch-Gordan coefficients. It provides a tool of measurement of chiral symmetry in relativistic composite systems.
Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations
Entanglement quantification by local unitaries
A. Monras; Adesso, G.; Giampaolo, S. M.; Gualdi, G.; Davies, G. B.; Illuminati, F.
2011-01-01
Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitaries play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as "mirror entanglement". They are constructed by first considering the (squared) Hilbert-S...
Ampcalculator (AMPC) is a Mathematica copyright based program that was made publicly available some time ago by Unterdorfer and Ecker. It enables the user to compute several processes at one loop (upto O(p 4)) in SU(3) chiral perturbation theory. They include computing matrix elements and form factors for strong and non-leptonic weak processes with at most six external states. It was used to compute some novel processes and was tested against well-known results by the original authors. Here we present the results of several thorough checks of the package. Exhaustive checks performed by the original authors are not publicly available, and hence the present effort. Some new results are obtained from the software especially in the kaon odd-intrinsic parity non-leptonic decay sector involving the coupling G27. Another illustrative set of amplitudes at tree level we provide is in the context of τ-decays with several mesons including quark mass effects, of use to the BELLE experiment. All eight meson-meson scattering amplitudes have been checked. The Kaon-Compton amplitude has been checked and a minor error in the published results has been pointed out. This exercise is a tutorial-based one, wherein several input and output notebooks are also being made available as ancillary files on the arXiv. Some of the additional notebooks we provide contain explicit expressions that we have used for comparison with established results. The purpose is to encourage users to apply the software to suit their specific needs. An automatic amplitude generator of this type can provide error-free outputs that could be used as inputs for further simplification, and in varied scenarios such as applications of chiral perturbation theory at finite temperature, density and volume. This can also be used by students as a learning aid in low-energy hadron dynamics. (orig.)
Ananthanarayan, B.; Das, Diganta; Sentitemsu Imsong, I.
2012-10-01
Ampcalculator (AMPC) is a Mathematica © based program that was made publicly available some time ago by Unterdorfer and Ecker. It enables the user to compute several processes at one loop (upto O( p 4) in SU(3) chiral perturbation theory. They include computing matrix elements and form factors for strong and non-leptonic weak processes with at most six external states. It was used to compute some novel processes and was tested against well-known results by the original authors. Here we present the results of several thorough checks of the package. Exhaustive checks performed by the original authors are not publicly available, and hence the present effort. Some new results are obtained from the software especially in the kaon odd-intrinsic parity non-leptonic decay sector involving the coupling G 27. Another illustrative set of amplitudes at tree level we provide is in the context of τ-decays with several mesons including quark mass effects, of use to the BELLE experiment. All eight meson-meson scattering amplitudes have been checked. The Kaon-Compton amplitude has been checked and a minor error in the published results has been pointed out. This exercise is a tutorial-based one, wherein several input and output notebooks are also being made available as ancillary files on the arXiv. Some of the additional notebooks we provide contain explicit expressions that we have used for comparison with established results. The purpose is to encourage users to apply the software to suit their specific needs. An automatic amplitude generator of this type can provide error-free outputs that could be used as inputs for further simplification, and in varied scenarios such as applications of chiral perturbation theory at finite temperature, density and volume. This can also be used by students as a learning aid in low-energy hadron dynamics.
Phenomenological analysis of ε'/ε within an effective chiral Lagrangian approach at O(p6)
We have combined a new systematic calculation of mesonic matrix elements at O(p6) from an effective chiral Lagrangian approach with Wilson coefficients from [1], derived in the framework of perturbative QCD, and restricted partly by experimental data. We derive complete expressions for K → 2π amplitudes and compare the results for ε'/ε with experiment
Novitsky, Andrey V; Zhukovsky, Sergei V
2010-01-01
The electronic Lorentz theory is employed to determine the electromagnetic response of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the effective permittivity tensor of the metamaterial is calculated. Whenever the split ring lacks in-plane mirror symmetry, the corresponding permit- tivity tensor has a crystallographic structure of an elliptically dichroic medium, and the metamaterial exhibits optical properties of planar chiral structures. Its transmission spectra are different for right-handed vs. left- handed circular polarization of the incident wave, so the structure changes its transmittance when the direction of incidence is reversed. The magnitude of this change is shown to be related to the geometric parameters of the split ring. The proposed approach can be straightforwardly generalized to a wide variety of metal-dielectric metamaterial geometries.
On unitary reconstruction of linear optical networks
Tillmann, Max; Walther, Philip
2015-01-01
Linear optical elements are pivotal instruments in the manipulation of classical and quantum states of light. The vast progress in integrated quantum photonic technology enables the implementation of large numbers of such elements on chip while providing interferometric stability. As a trade-off these structures face the intrinsic challenge of characterizing their optical transformation as individual optical elements are not directly accessible. Thus the unitary transformation needs to be reconstructed from a dataset generated with having access to the input and output ports of the device only. Here we present a novel approach to unitary reconstruction that significantly improves upon existing approaches. We compare its performance to several approaches via numerical simulations for networks up to 14 modes. We show that an adapted version of our approach allows to recover all mode-dependent losses and to obtain highest reconstruction fidelities under such conditions.
A new approach to derive Pfaffian structures for random matrix ensembles
Correlation functions for matrix ensembles with orthogonal and unitary-symplectic rotation symmetry are more complicated to calculate than in the unitary case. The supersymmetry method and the orthogonal polynomials are two techniques to tackle this task. Recently, we presented a new method to average ratios of characteristic polynomials over matrix ensembles invariant under the unitary group. Here, we extend this approach to ensembles with orthogonal and unitary-symplectic rotation symmetry. We show that Pfaffian structures can be derived for a wide class of orthogonal and unitary-symplectic rotation invariant ensembles in a unifying way. This also includes those for which this structure was not known previously, as the real Ginibre ensemble and the Gaussian real chiral ensemble with two independent matrices as well.
Nuclear electromagnetic currents from chiral EFT
Using the method of unitary transformation in combination with chiral effective field theory we derive the pion exchange contributions to the two-nucleon electromagnetic current. A formal definition of the current operator in this scheme and the power counting is presented. We discuss the implications of additional unitary transformations that have to be present to ensure the renormalizability of the one-pion exchange current. Further, we give explicit and compact results for the current in coordinate-space.
Ananthanarayan, B; Imsong, I Sentitemsu
2012-01-01
AMPCALCULATOR is a mathematica-based program that was made publicly available some time ago by Unterdorfer and Ecker. It enables the user to compute several processes upto $O(p^4)$ in SU(3) chiral perturbation theory. They include computing matrix elements and form factors for strong and nonleptonic weak processes with at most six external states. It was used to compute some novel processes and was tested against some well-known results by the original authors. Here we present the results of several thorough checks of the package. Exhaustive checks performed by the original authors are not publicly available, and hence the present effort. Some new results are obtained from the software especially in the kaon odd-intrinsic parity nonleptonic decay sector involving the coupling $G_{27}$. Another illustrative set of amplitudes at tree level we provide is in the context of $\\tau$-decays with several mesons including quark mass effects, of use to the BELLE experiment. All eight meson-meson scattering amplitudes ha...
Haupert, Levi M.; Simpson, Garth J.
2009-05-01
The past decade has witnessed the emergence of new measurement approaches and applications for chiral thin films and materials enabled by the observations of the high sensitivity of second-order nonlinear optical measurements to chirality. In thin films, the chiral response to second harmonic generation and sum frequency generation (SFG) from a single molecular monolayer is often comparable with the achiral response. The chiral specificity also allows for symmetry-allowed SFG in isotropic chiral media, confirming predictions made ˜50 years ago. With these experimental demonstrations in hand, an important challenge is the construction of intuitive predictive models that allow the measured chiral response to be meaningfully related back to molecular and macromolecular structure. This review defines and considers three distinct mechanisms for chiral effects in uniaxially oriented assemblies: orientational chirality, intrinsic chirality, and isotropic chirality. The role of each is discussed in experimental and computational studies of bacteriorhodopsin films, binaphthol, and collagen. Collectively, these three model systems support a remarkably simple framework for quantitatively recovering the measured chiral-specific activity.
An Operator Formalism for Unitary Matrix Models
Anagnostopoulos, K. N.; Bowick, M. J.; Ishibashi, N.
We analyze the double scaling limit of unitary matrix models in terms of trigonometric orthogonal polynomials on the circle. In particular we find a compact formulation of the string equation at the kth multicritical point in terms of pseudodifferential operators and a corresponding action principle. We also relate this approach to the mKdV hierarchy which appears in the analysis in terms of conventional orthogonal polynomials on the circle.
Entanglement Continuous Unitary Transformations
Sahin, S; Orus, R
2016-01-01
Continuous unitary transformations are a powerful tool to extract valuable information out of quantum many-body Hamiltonians, in which the so-called flow equation transforms the Hamiltonian to a diagonal or block-diagonal form in second quantization. Yet, one of their main challenges is how to approximate the infinitely-many coupled differential equations that are produced throughout this flow. Here we show that tensor networks offer a natural and non-perturbative truncation scheme in terms of entanglement. The corresponding scheme is called "entanglement-CUT" or eCUT. It can be used to extract the low-energy physics of quantum many-body Hamiltonians, including quasiparticle energy gaps. We provide the general idea behind eCUT and explain its implementation for finite 1d systems using the formalism of matrix product operators, and we present proof-of-principle results for the spin-1/2 1d quantum Ising model in a transverse field. Entanglement-CUTs can also be generalized to higher dimensions and to the thermo...
Unitary Transformation in Quantum Teleportation
WANG Zheng-Chuan
2006-01-01
In the well-known treatment of quantum teleportation, the receiver should convert the state of his EPR particle into the replica of the unknown quantum state by one of four possible unitary transformations. However, the importance of these unitary transformations must be emphasized. We will show in this paper that the receiver cannot transform the state of his particle into an exact replica of the unknown state which the sender wants to transfer if he has not a proper implementation of these unitary transformations. In the procedure of converting state, the inevitable coupling between EPR particle and environment which is needed by the implementation of unitary transformations will reduce the accuracy of the replica.
Linear maps respecting unitary conjugation
Bhat, B V Rajarama
2011-01-01
We characterize linear maps on von Neumann algebras which leave every unital subalgebra invariant. We use this characterization to determine linear maps which respect unitary conjugation, answering a question of M. S. Moslehian.
First-order conservation laws in a chiral medium II: a covariant approach
The first-order conservation laws associated with the symmetric zilch Z and its antisymmetric companion Y previously derived in a chiral medium at rest are extended to an arbitrary frame. (author). 5 refs
Chiral approach to nuclear matter: Role of explicit short-range NN-terms
Fritsch, S
2003-01-01
We extend a recent chiral approach to nuclear matter by including the most general (momentum-independent) NN-contact interaction. Iterating this two-parameter contact-vertex with itself and with one-pion exchange the emerging energy per particle exhausts all terms possible up-to-and-including fourth order in the small momentum expansion. The equation of state of pure neutron matter, $\\bar E_n(k_n)$, can be reproduced very well up to quite high neutron densities of $\\rho_n=0.5\\fmd$ by adjusting the strength of a repulsive $nn$-contact interaction. Binding and saturation of isospin-symmetric nuclear matter is a generic feature of our perturbative calculation. Fixing the maximum binding energy per particle to $-\\bar E(k_{f0})= 15.3 $MeV we find that any possible equilibrium density $\\rho_0$ lies below $\\rho_0^{\\rm max}=0.191\\fmd$. The additional constraint from the neutron matter equation of state leads however to a somewhat too low saturation density of $\\rho_0 =0.134 \\fmd$. We also investigate the effects of t...
A C–H oxidation approach for streamlining synthesis of chiral polyoxygenated motifs
Covell, Dustin J.; White, M. Christina
2013-01-01
Chiral oxygenated molecules are pervasive in natural products and medicinal agents; however, their chemical syntheses often necessitate numerous, wasteful steps involving functional group and oxidation state manipulations. Herein a strategy for synthesizing a readily diversifiable class of chiral building blocks, allylic alcohols, through sequential asymmetric C—H activation/resolution is evaluated against the state-of-the-art. The C—H oxidation routes’ capacity to strategically introduce oxy...
Unitary spaces on Clifford algebras
Marchuk, N. G.; Shirokov, D. S.
2007-01-01
For the complex Clifford algebra Cl(p,q) of dimension n=p+q we define a Hermitian scalar product. This scalar product depends on the signature (p,q) of Clifford algebra. So, we arrive at unitary spaces on Clifford algebras. With the aid of Hermitian idempotents we suggest a new construction of, so called, normal matrix representations of Clifford algebra elements. These representations take into account the structure of unitary space on Clifford algebra.
Understanding complex chiral plasmonics
Duan, Xiaoyang; Yue, Song; Liu, Na
2015-10-01
Chiral nanoplasmonics exhibits great potential for novel nanooptical devices due to the generation of a strong chiroptical response within nanoscale metallic structures. Recently, a number of different approaches have been utilized to create chiral nanoplasmonic structures. However, particularly for tailoring nanooptical chiral sensing devices, the understanding of the resulting chiroptical response when coupling chiral and achiral structures together is crucial and has not been completely understood to date. Here, we present a thorough and step-by-step experimental study to understand the intriguing chiral-achiral coupling scheme. We set up a hybrid plasmonic system, which bears resemblance to the `host-guest' system in supramolecular chemistry to analyze and explain the complex chiral response both at the chiral and achiral plasmonic resonances. We also provide an elegant and simple analytical model, which can describe, predict, and comprehend the chiroptical spectra in detail. Our study will shed light on designing well-controlled chiral-achiral coupling platforms for reliable chiral sensing.Chiral nanoplasmonics exhibits great potential for novel nanooptical devices due to the generation of a strong chiroptical response within nanoscale metallic structures. Recently, a number of different approaches have been utilized to create chiral nanoplasmonic structures. However, particularly for tailoring nanooptical chiral sensing devices, the understanding of the resulting chiroptical response when coupling chiral and achiral structures together is crucial and has not been completely understood to date. Here, we present a thorough and step-by-step experimental study to understand the intriguing chiral-achiral coupling scheme. We set up a hybrid plasmonic system, which bears resemblance to the `host-guest' system in supramolecular chemistry to analyze and explain the complex chiral response both at the chiral and achiral plasmonic resonances. We also provide an elegant
Universal superreplication of unitary gates.
Chiribella, G; Yang, Y; Huang, C
2015-03-27
Quantum states obey an asymptotic no-cloning theorem, stating that no deterministic machine can reliably replicate generic sequences of identically prepared pure states. In stark contrast, we show that generic sequences of unitary gates can be replicated deterministically at nearly quadratic rates, with an error vanishing on most inputs except for an exponentially small fraction. The result is not in contradiction with the no-cloning theorem, since the impossibility of deterministically transforming pure states into unitary gates prevents the application of the gate replication protocol to states. In addition to gate replication, we show that N parallel uses of a completely unknown unitary gate can be compressed into a single gate acting on O(log_{2}N) qubits, leading to an exponential reduction of the amount of quantum communication needed to implement the gate remotely. PMID:25860728
We juxtapose two approaches to the representations of the super-Heisenberg group. Physical one, sometimes called concrete approach, based on the super-wave functions depending on the anti-commuting variables, yielding the harmonic superanalysis and recently developed strict theory of unitary representations of the nilpotent super Lie groups covering the unitary representations of the super-Heisenberg group
On the pole content of coupled channels chiral approaches used for the $\\bar{K}N$ system
Cieplý, A; Meißner, Ulf-G; Smejkal, J
2016-01-01
Several theoretical groups describe the antikaon-nucleon interaction at low energies within approaches based on the chiral SU(3) dynamics and including next-to-leading order contributions. We present a comparative analysis of the pertinent models and discuss in detail their pole contents. It is demonstrated that the approaches lead to very different predictions for the $K^{-}p$ amplitude extrapolated to subthreshold energies as well as for the $K^{-}n$ amplitude. The origin of the poles generated by the models is traced to the so-called zero coupling limit, in which the inter-channel couplings are switched off. This provides new insights into the pole contents of the various approaches. In particular, different concepts of forming the $\\Lambda(1405)$ resonance are revealed and constraints related to the appearance of such poles in a given approach are discussed.
Optimal cloning of unitary transformations
Chiribella G.; D'Ariano G.M.; Perinotti P.
2008-01-01
After proving a general no-cloning theorem for black boxes, we derive the optimal universal cloning of unitary transformations, from one to two copies. The optimal cloner is realized by quantum channels with memory, and greately outperforms the optimal measure-and-reprepare cloning strategy. Applications are outlined, including two-way quantum cryptographic protocols.
Single-particle potential in a chiral approach to nuclear matter including short-range NN-terms
We extend a recent chiral approach to nuclear matter of Lutz et al. (Phys. Lett. B 474,7(2000)) by calculating the underlying (complex-valued) single-particle potential U(p,kf)+iW(p,kf). The potential for a nucleon at the bottom of the Fermi sea, U(0,kf0)=- 20.0 MeV, comes out as much too weakly attractive in this approach. Even more seriously, the total single-particle energy does not rise monotonically with the nucleon momentum p, implying a negative effective nucleon mass at the Fermi surface. Also, the imaginary single-particle potential, W(0,kf0)=51.1 MeV, is too large. More realistic single-particle properties together with a good nuclear-matter equation of state can be obtained if the short-range contributions of non-pionic origin are treated in mean-field approximation (i.e. if they are not further iterated with 1π-exchange). We also consider the equation of state of pure neutron matter anti En(kn) and the asymmetry energy A(kf) in that approach. The downward bending of these quantities above nuclear-matter saturation density seems to be a generic feature of perturbative chiral pion-nucleon dynamics. (orig.)
Implementation of discrete unitary transformations by multimode waveguide holograms.
Tseng, Shuo-Yen; Kim, Younggu; Richardson, Christopher J K; Goldhar, Julius
2006-07-10
Integration of holograms into multimode waveguides allows the implementation of arbitrary unitary mode transformations and unitary matrix-vector multiplication. Theoretical analysis is used to justify a design approach to implement specific functions in these devices. Based on this approach, a compact mode-order converter, a Hadamard transformer, and a spatial pattern generator-correlator are proposed and analyzed. Beam propagation simulations are used to verify the theoretical calculations and to address bandwidth, scalability, and fabrication criteria. Optical pattern generators were successfully fabricated using standard photolithographic techniques to demonstrate the feasibility of the devices. PMID:16807593
Topics in three flavor chiral dynamics
Nissler, Robin
2007-07-01
In this work, we investigate several processes in low-energy hadron physics by combining chiral perturbation theory (ChPT), the effective field theory of quantum chromodynamics (QCD) at low energies, with a unitarization method based on the Bethe-Salpeter equation. Such so-called chiral unitary approaches are capable of describing processes in the three flavor sector of the strong interaction which involve substantial effects from final-state interactions and the excitation of (subthreshold) resonances, a domain where the perturbative framework of ChPT is not applicable. In part I of this work we study {eta} and {eta}' decays which constitute a perfect tool to examine symmetries and symmetry breaking patterns of QCD being incorporated in a model-independent fashion in ChPT. In particular, these decays allow to investigate the breaking of isospin symmetry due to the light quark mass difference m{sub d}-m{sub u} as well as effects of anomalies stemming from the quantum nature of QCD. For these reasons the decays of {eta} and {eta}' have also attracted considerable experimental interest. They are currently under investigation at several facilities including KLOE rate at DA{phi}NE, Crystal Ball at MAMI, WASA-at-COSY, VES at IHEP, and CLEO at CESR. In part II we investigate low-energy meson-baryon scattering in the strangeness S=-1 sector which is dominated by the {lambda}(1405) resonance immediately below the anti KN threshold. The anti KN interaction below threshold is of relevance for the quest of possible deeply bound anti K-nuclear clusters and has recently received an additional tight constraint: the K{sup -}p scattering length as determined from kaonic hydrogen by the KEK and the DEAR collaborations. Apart from successfully describing a large amount of experimental data and furnishing predictions for yet unmeasured quantities, our calculations allow to interrelate different experimental observables providing important consistency tests of experiments. E
Exact and approximate unitary 2-designs and their application to fidelity estimation
We develop the concept of a unitary t-design as a means of expressing operationally useful subsets of the stochastic properties of the uniform (Haar) measure on the unitary group U(2n) on n qubits. In particular, sets of unitaries forming 2-designs have wide applicability to quantum information protocols. We devise an O(n)-size in-place circuit construction for an approximate unitary 2-design. We then show that this can be used to construct an efficient protocol for experimentally characterizing the fidelity of a quantum process on n qubits with quantum circuits of size O(n) without requiring any ancilla qubits, thereby improving upon previous approaches.
Teleportation of M-Qubit Unitary Operations
郑亦庄; 顾永建; 郭光灿
2002-01-01
We discuss teleportation of unitary operations on a two-qubit in detail, then generalize the bidirectional state teleportation scheme from one-qubit to M-qubit unitary operations. The resources required for the optimal implementation of teleportation of an M-qubit unitary operation using a bidirectional state teleportation scheme are given.
K{sup -} nuclear quasi-bound states in a chirally motivated coupled-channel approach
Mares, Jiri, E-mail: mares@ujf.cas.cz [Nuclear Physics Institute (Czech Republic)
2012-05-15
K{sup }- nuclear optical potentials are constructed from in-medium K-bar N scattering amplitudes within a chirally motivated coupled-channel model. The strong energy and density dependence of the scattering amplitudes at and below threshold leads to K{sup }- potential depths -Re V{sub K{sup -}}({rho}{sub 0}) approx. 80 - 100 MeV. Self consistent calculations of K{sup }- nuclear quasi-bound states are discussed.
Chiral forces and molecular dissymmetry
Chiral molecules leading to helical macromolecules seem to preserve information and extend it better. In the biological world RNA is the very paradigm for self-replication, elongation and autocatalytic editing. The nucleic acid itself is not chiral. It acquires its chirality by association with D-sugars. Although the chiral information or selectivity put in by the unit monomer is no longer of much interest to the biologists - they tend to leave it to the Darwinian selection principle to take care of it as illustrated by Frank's model - it is vital to understand the origin of chirality. There are three different approaches for the chiral origin of life: (1) Phenomenological, (2) Electromagnetic molecular and Coriolis forces and (3) Atomic or nuclear force, the neutral weak current. The phenomenological approach involves spontaneous symmetry breaking fluctuations in far for equilibrium systems or nucleation and crystallization. Chance plays a major role in the chiral molecule selected
Unitary equivalence of quantum walks
Highlights: • We have found unitary equivalent classes in coined quantum walks. • A single parameter family of coin operators is sufficient to realize all simple one-dimensional quantum walks. • Electric quantum walks are unitarily equivalent to time dependent quantum walks. - Abstract: A simple coined quantum walk in one dimension can be characterized by a SU(2) operator with three parameters which represents the coin toss. However, different such coin toss operators lead to equivalent dynamics of the quantum walker. In this manuscript we present the unitary equivalence classes of quantum walks and show that all the nonequivalent quantum walks can be distinguished by a single parameter. Moreover, we argue that the electric quantum walks are equivalent to quantum walks with time dependent coin toss operator
Localized Excitations from Localized Unitary Operators
Sivaramakrishnan, Allic
2016-01-01
Localized unitary operators are basic probes of locality and causality in quantum systems: localized unitary operators create localized excitations in entangled states. Working with an explicit form, we explore the properties of these operators in quantum mechanics and quantum field theory. We show that, unlike unitary operators, local non-unitary operators generically create non-local excitations. We present a local picture for quantum systems in which localized experimentalists can only act through localized Hamiltonian deformations, and therefore localized unitary operators. We demonstrate that localized unitary operators model certain quantum quenches exactly. We show how the Reeh-Schlieder theorem follows intuitively from basic properties of entanglement, non-unitary operators, and the local picture. We show that a recent quasi-particle picture for excited-state entanglement entropy in conformal field theories is not universal for all local operators. We prove a causality relation for entanglement entrop...
Unitary Transformation in Probabilistic Teleportation
Tian, Xiu-Lao; Zhang, Wei; Xi, Xiao-Qiang
2012-01-01
We proposed a general transformation in probabilistic teleportation, which is based on different entanglement matching coefficients $K$ corresponding to different unitary evolution which provides one with more flexible evolution method experimentally. Through analysis based on the Bell basis and generalized Bell basis measurement for two probabilistic teleportation, we suggested a general probability of successful teleportation, which is not only determined by the entanglement degree of trans...
Branching problems of unitary representations
Kobayashi, Toshiyuki
2003-01-01
The irreducible decomposition of a unitary representation often contains continuous spectrum when restricted to a non-compact subgroup. The author singles out a nice class of branching problems where each irreducible summand occurs discretely with finite multiplicity (admissible restrictions). Basic theory and new perspectives of admissible restrictions are presented from both analytic and algebraic view points. We also discuss some applications of admissible restrictions to modular varieties...
An Analytic Approach to Sunset Diagrams in Chiral Perturbation Theory: Theory and Practice
Ananthanarayan, B; Ghosh, Shayan; Hebbar, Aditya
2016-01-01
We demonstrate the use of several code implementations of the Mellin-Barnes method available in the public domain to derive analytic expressions for the sunset diagrams that arise in the two-loop contribution to the pion mass and decay constant in three-flavoured chiral perturbation theory. We also provide results for all possible two-mass configurations of the sunset integral, and derive a new one-dimensional integral representation for the one mass sunset integral with arbitrary external momentum. Thoroughly annotated Mathematica notebooks are provided as ancillary files, which may serve as pedagogical supplements to the methods described in this paper.
Chiral dynamics of baryon resonances and hadrons in a nuclear medium
E Oset; D Cabrera; V K Magas; L Roca; S Sarkar; M J Vicente Vacas; A Ramos
2006-04-01
In these lectures I make an introduction to chiral unitary theory applied to the meson-baryon interaction and show how several well-known resonances are dynamically generated, and others are predicted. Two very recent experiments are analyzed, one of them showing the existence of two (1405) states and the other one providing support for the (1520) resonance as a quasi-bound state of $\\sum (1385) $. The use of chiral Lagrangians to account for the hadronic interaction at the elementary level introduces a new approach to deal with the modification of meson and baryon properties in a nuclear medium. Examples of it for $\\bar{K}$, and modification in the nuclear medium are presented.
Efficient quantum circuits for diagonal unitaries without ancillas
The accurate evaluation of diagonal unitary operators is often the most resource-intensive element of quantum algorithms such as real-space quantum simulation and Grover search. Efficient circuits have been demonstrated in some cases but generally require ancilla registers, which can dominate the qubit resources. In this paper, we give a simple way to construct efficient circuits for diagonal unitaries without ancillas, using a correspondence between Walsh functions and a basis for diagonal operators. This correspondence reduces the problem of constructing the minimal-depth circuit within a given error tolerance, for an arbitrary diagonal unitary eif(x-^) in the |x〉 basis, to that of finding the minimal-length Walsh-series approximation to the function f(x). We apply this approach to the quantum simulation of the classical Eckart barrier problem of quantum chemistry, demonstrating that high-fidelity quantum simulations can be achieved with few qubits and low depth
Chiral supergravity and anomalies
Mielke, E W; Macias, Alfredo; Mielke, Eckehard W.
1999-01-01
Similarily as in the Ashtekar approach, the translational Chern-Simons term is, as a generating function, instrumental for a chiral reformulation of simple (N=1) supergravity. After applying the algebraic Cartan relation between spin and torsion, the resulting canonical transformation induces not only decomposition of the gravitational fields into selfdual and antiselfdual modes, but also a splitting of the Rarita-Schwinger fields into their chiral parts in a natural way. In some detail, we also analyze the consequences for axial and chiral anomalies.
Implications of the Oklo Phenomenon in a Chiral Approach to Nuclear Matter
It has been customary to use data from the Oklo natural nuclear reactor to place bounds on the change that has occurred in the electromagnetic fine structure constant α over the last 2 billion years. Alternatively, an analysis could be based on a recently proposed expression for shifts in resonance energies which relates them to changes in both α and the average mq of the u and d current quark masses, and which makes explicit the dependence on mass number A and atomic number Z. (Recent model independent results on hadronic σ -terms suggest sensitivity to the strange quark mass is negligible.) The most sophisticated analysis, to date, of the quark mass term invokes a calculation of the nuclear mean-field within the Walecka model of quantum hadrodynamics. We comment on this study and consider an alternative in which the link to low-energy quantum chromodynamics and its pattern of chiral symmetry-breaking is more readily discernible. Specifically, we investigate the sensitivity to changes in the pion mass Mπ of a single nucleon potential determined by an in-medium chiral perturbation theory (χPT) calculation which includes virtual Δ-excitations. Subject to some reasonable assumptions about low-energy constants, we confirm that the mq-contribution to resonance shifts is enhanced by a factor of 10 or so relative to the α-term and deduce that the Oklo data for Sm imply that |mq(Oklo)−mq(now)|≲10−9 mq(now) . (author)
Goldstein Gary R.
2015-01-01
Full Text Available Nucleon spin structure, transversity and the tensor charge are of central importance to understanding the role of QCD in hadronic physics. A new approach to measuring orbital angular momenta of quarks in the proton via twist 3 GPDs is shown. The “flexible parametrization” of chiral even GPDs is reviewed and its transformation into the chiral odd sector is discussed. The resulting parametrization is applied to recent data on π0 and η electroproduction.
Hadronic interactions from effective chiral Lagrangians of quarks and gluons
We discuss the combined used of the techniques of effective chiral field theory and the field theoretic method known as Fock-Tani representation to derive effective hadron interactions. The Fock-Tani method is based on a change of representation by means of a unitary transformation such that the composite hadrons are redescribed by elementary-particle field operators. Application of the unitary transformation on the microscopic quark-quark interaction derived from a chiral effective Lagrangian leads to chiral effective interactions describing all possible processes involving hadrons and their constituents. The formalism is illustrated by deriving the one-pion-exchange potential between the nucleons using the quark-gluon effective chiral Lagrangian of Manohar and Georgi. We also present the results of a study of the saturation properties of the nuclear matter using this formalism. (author). 9 refs., 2 figs
The K¯N→KΞ reaction in coupled channel chiral models up to next-to-leading order
We study the meson-baryon interaction in S-wave in the strangeness S=−1 sector using a chiral unitary approach based on a next-to-leading order chiral SU(3) Lagrangian. We fit our model to the large set of experimental data in different two-body channels. We pay particular attention to the K¯N→KΞ reaction, where the effect of the next-to-leading order terms in the Lagrangian are sufficiently large to be observed, since at tree level the cross section of this reaction is zero. For these channels we improve our approach by phenomenologically taking into account effects of the high spin hyperonic resonances
Truncations of random unitary matrices
Zyczkowski, K; Zyczkowski, Karol; Sommers, Hans-Juergen
1999-01-01
We analyze properties of non-hermitian matrices of size M constructed as square submatrices of unitary (orthogonal) random matrices of size N>M, distributed according to the Haar measure. In this way we define ensembles of random matrices and study the statistical properties of the spectrum located inside the unit circle. In the limit of large matrices, this ensemble is characterized by the ratio M/N. For the truncated CUE we derive analytically the joint density of eigenvalues from which easily all correlation functions are obtained. For N-M fixed and N--> infinity the universal resonance-width distribution with N-M open channels is recovered.
Unitary Housing Regimes in Transition
Bengtsson, Bo; Jensen, Lotte
2013-01-01
institutional detail. Both systems have corporatist features, however in Denmark public housing is based on local tenant democracy and control, and in Sweden on companies owned and controlled by the municipalities, combined with a centralized system of rent negotiations. In the paper the present challenges to...... Scandinavia, and elsewhere, are under challenge from strong political and economic forces. These challenges can be summarized as economic cutbacks, privatization and Europeanization. Although both the Danish and the Swedish housing system are universal and unitary in character, they differ considerably in...
Unitary Isobar Model - MAID2007
Drechsel, D.; Kamalov, S. S.; Tiator, L.
2007-01-01
The unitary isobar model MAID2007 has been developed to analyze the world data of pion photo- and electroproduction. The model contains both a common background and several resonance terms. The background is unitarized according to the K-matrix prescription, and the 13 four-star resonances with masses below 2 GeV are described by appropriately unitarized Breit-Wigner forms. The data have been analyzed by both single-energy and global fits, and the transverse and longitudinal helicity amplitud...
What unitary matrix models are not?
Lafrance, R; Lafrance, Rene; Myers, Robert
1993-01-01
We report results of two investigations of the double-scaling equations for the unitary matrix models. First, the fixed area partition functions have all positive coefficients only for the first four critical points. This implies that the critical points at $k\\ge5$ describe non-unitary continuum theories. Secondly, we examine a conjectured connection to branched polymers, but find that the scaling solutions of the unitary models do not agree with those of a particular model describing branched polymers.
Defining a Unitary Business: An Economist's View
Charles E. McLure, Jr.
1983-01-01
The definition of a unitary business has figured prominently in several recent decisions of the U.S. Supreme Court on the constitutionality of state corporate income taxes. This paper employs economic analysis to frame a three part test of whether a unitary business exists. Underlying the tests is the notion that a unitary business exists when separate accounting can not satisfactorily isolate the profits of individual firms. The first test is common control. The second is whether transfer pr...
Adjacency Algebra of Unitary Cayley Graph
A. Satyanarayana Reddy
2013-02-01
Full Text Available A few properties of unitary Cayley graphs are explored using their eigenvalues. It is shown that the adjacency algebra of a unitary Cayley graph is a coherent algebra. Finally, a class of unitary Cayley graphs that are distance regular are also obtained.Key Words: Adjacency Algebra, Circulant Graph, Coherent Algebra, Distance Regular Graph,Ramanujan's sum .AMS(2010: 05C25, 05C50
Inoue, Yoshihisa
2004-01-01
Direct Asymmetric Photochemistry with Circularly Polarized Light, H. RauCoherent Laser Control of the Handedness of Chiral Molecules, P. Brumer and M. ShapiroMagnetochiral Anisotropy in Asymmetric Photochemistry, G.L.J.A.RikkenEnantiodifferentiating Photosensitized Reactions, Y. InoueDiastereodifferentiating Photoreactions, N. Hoffmann and J.-P. PeteChirality in Photochromism, Y. Yokoyama and M. SaitoChiral Photochemistry with Transition Metal Complexes, S. Sakaki and T. HamadaTemplate-Induced Enantioselective Photochemical Reactions in S
Kharzeev, Dmitri E.; Yee, Ho-Ung
2012-01-01
We consider the properties of electric circuits involving Weyl semimetals. The existence of the anomaly-induced chiral magnetic current in a Weyl semimetal subjected to magnetic field causes an interesting and unusual behavior of such circuits. We consider two explicit examples: i) a circuit involving the "chiral battery" and ii) a circuit that can be used as a "quantum amplifier" of magnetic field. The unique properties of these circuits stem from the chiral anomaly and may be utilized for c...
Singular Value Decomposition for Unitary Symmetric Matrix
ZOUHongxing; WANGDianjun; DAIQionghai; LIYanda
2003-01-01
A special architecture called unitary sym-metric matrix which embodies orthogonal, Givens, House-holder, permutation, and row (or column) symmetric ma-trices as its special cases, is proposed, and a precise corre-spondence of singular values and singular vectors between the unitary symmetric matrix and its mother matrix is de-rived. As an illustration of potential, it is shown that, for a class of unitary symmetric matrices, the singular value decomposition (SVD) using the mother matrix rather than the unitary symmetric matrix per se can save dramatically the CPU time and memory without loss of any numerical precision.
Unitary Integrals and Related Matrix Models
Morozov, A
2009-01-01
Concise review of the basic properties of unitary matrix integrals. They are studied with the help of the three matrix models: the ordinary unitary model, Brezin-Gross-Witten model and the Harish-Charndra-Itzykson-Zuber model. Especial attention is paid to the tricky sides of the story, from De Wit-t'Hooft anomaly in unitary integrals to the problem of correlators with Itzykson-Zuber measure. Of technical tools emphasized is the method of character expansions. The subject of unitary integrals remains highly under-investigated and a lot of new results are expected in this field when it attracts sufficient attention.
Spectral study of a chiral limit without chiral condensate
Bietenholz, Wolfgang
2009-01-01
Random Matrix Theory (RMT) has elaborated successful predictions for Dirac spectra in field theoretical models. However, a generic assumption by RMT has been a non-vanishing chiral condensate $\\Sigma$ in the chiral limit. Here we consider the 2-flavour Schwinger model, where this assumption does not hold. We simulated this model with dynamical overlap hypercube fermions, and entered terra incognita by analysing this Dirac spectrum. The usual RMT prediction for the unfolded level spacing distribution in a unitary ensemble is precisely confirmed. The microscopic spectrum does not perform a Banks-Casher plateau. Instead the obvious expectation is a density of the lowest eigenvalue $\\lambda_{1}$ which increases $\\propto \\lambda_{1}^{1/3}$. That would correspond to a scale-invariant parameter $\\propto \\lambda V^{3/4}$, which is, however, incompatible with our data. Instead we observe to high precision a scale-invariant parameter $z \\propto \\lambda V^{5/8}$. This surprising result implies a microscopic spectral den...
The unitary convolution approximation for heavy ions
Grande, P L
2002-01-01
The convolution approximation for the impact-parameter dependent energy loss is reviewed with emphasis on the determination of the stopping force for heavy projectiles. In this method, the energy loss in different impact-parameter regions is well determined and interpolated smoothly. The physical inputs of the model are the projectile-screening function (in the case of dressed ions), the electron density and oscillators strengths of the target atoms. Moreover, the convolution approximation, in the perturbative mode (called PCA), yields remarkable agreement with full semi-classical-approximation (SCA) results for bare as well as for screened ions at all impact parameters. In the unitary mode (called UCA), the method contains some higher-order effects (yielding in some cases rather good agreement with full coupled-channel calculations) and approaches the classical regime similar as the Bohr model for large perturbations (Z/v>>1). The results are then used to compare with experimental values of the non-equilibri...
Suliman, FakhrEldin O.; Elbashir, Abdalla A.
2012-07-01
Using capillary electrophoresis baclofen (BF) enantiomers were separated only in the presence of β-cyclodextrin (βCD) as a chiral selector when added to the background electrolyte. Proton nuclear magnetic resonance and electrospray ionization mass spectrometry (ESI-MS) techniques were used to determine the structure of the BF-βCD inclusion complexes. From the MS data BF was found to form a 1:1 complex with α- and βCD, while the NMR data suggest location of the aromatic ring of BF into the cyclodextrin cavity. A molecular modeling study, using the semiempirical PM6 calculations was used to investigate the mechanism of enantiodifferentiation of BF with cyclodextrins. Optimization of the structures of the complexes by PM6 method indicated that separation is obtained in the presence of β-CD due to a large binding energy difference (ΔΔE) of 46.8 kJ mol-1 between S-BF-βCD and R-BF-βCD complexes. In the case of αCD complexes ΔΔE was 1.3 kJ mol-1 indicating poor resolution between the two enantiomers. Furthermore, molecular dynamic simulations show that the formation of more stable S-BF-βCD complex compared to R-BF-β-CD complex is primarily due to differences in intermolecular hydrogen bonding.
The chiral anomaly in conformal and ordinary simple supergravity in Fujikawa's approach
In this contribution the authors reobtain the chiral anomaly of simple ordinary supergravity by means of Fujikawa's method as well as by the Pauli-Villars method. Then they present, as a new result, the axial anomaly for simple conformal supergravity. Axial anomalies have been discussed extensively in recent articles. For supergravity, the issue is, as usual, more subtle than elsewhere, because one must fix gauges and add ghosts for the fermions in the loop. The axial anomal in simple ordinary supergravity has been calculated by various methods. The authors begin by reobtaining the same result by means of the original Fujikawa method, since it is interesting in itself and will be used to illustrate certain aspects in the conformal computation. The authors show that using as regulator either the operator which is obtained directly from the classical action plus gauge fixing term, or simply the Dirac operator itself, yields the same result. The authors present the Pauli-Villars computation because it most clearly shows which regulator should be used for a given anomaly
Kallin, Catherine; Berlinsky, John
2016-05-01
Chiral superconductivity is a striking quantum phenomenon in which an unconventional superconductor spontaneously develops an angular momentum and lowers its free energy by eliminating nodes in the gap. It is a topologically non-trivial state and, as such, exhibits distinctive topological modes at surfaces and defects. In this paper we discuss the current theory and experimental results on chiral superconductors, focusing on two of the best-studied systems, Sr2RuO4, which is thought to be a chiral triplet p-wave superconductor, and UPt3, which has two low-temperature superconducting phases (in zero magnetic field), the lower of which is believed to be chiral triplet f-wave. Other systems that may exhibit chiral superconductivity are also discussed. Key signatures of chiral superconductivity are surface currents and chiral Majorana modes, Majorana states in vortex cores, and the possibility of half-flux quantum vortices in the case of triplet pairing. Experimental evidence for chiral superconductivity from μSR, NMR, strain, polar Kerr effect and Josephson tunneling experiments are discussed.
On Investigating GMRES Convergence using Unitary Matrices
Duintjer Tebbens, Jurjen; Meurant, G.; Sadok, H.; Strakoš, Z.
2014-01-01
Roč. 450, 1 June (2014), s. 83-107. ISSN 0024-3795 Grant ostatní: GA AV ČR(CZ) M100301201; GA MŠk(CZ) LL1202 Institutional support: RVO:67985807 Keywords : GMRES convergence * unitary matrices * unitary spectra * normal matrices * Krylov residual subspace * Schur parameters Subject RIV: BA - General Mathematics Impact factor: 0.939, year: 2014
Unitary Inequivalent Representations in Quantum Physics
Stepanian, Arman; Kohandel, Mahsa
2013-01-01
First we will discuss the concept of unitary inequivalentness in quantum physics. Then by giving some examples in the Quantum Field Theory(QFT), we will show the role of unitary inequivalent representations to understand some phenomena such as Hawking effect.
Kitaev honeycomb tensor networks: exact unitary circuits and applications
Schmoll, Philipp
2016-01-01
The Kitaev honeycomb model is a paradigm of exactly-solvable models, showing non-trivial physical properties such as topological quantum order, abelian and non-abelian anyons, and chirality. Its solution is one of the most beautiful examples of the interplay of different mathematical techniques in condensed matter physics. In this paper, we show how to derive a tensor network (TN) description of the eigenstates of this spin-1/2 model in the thermodynamic limit, and in particular for its ground state. In our setting, eigenstates are naturally encoded by an exact 3d TN structure made of fermionic unitary operators, corresponding to the unitary quantum circuit building up the many-body quantum state. In our derivation we review how the different "solution ingredients" of the Kitaev honeycomb model can be accounted for in the TN language, namely: Jordan-Wigner transformation, braidings of Majorana modes, fermionic Fourier transformation, and Bogoliubov transformation. The TN built in this way allows for a clear u...
Unitary dilation models of Turing machines in quantum mechanics
A goal of quantum-mechanical models of the computation process is the description of operators that model changes in the information-bearing degrees of freedom. Iteration of the operators should correspond to steps in the computation, and the final state of halting computations should be stable under iteration. The problem is that operators constructed directly from the process description do not have these properties. In general these operators annihilate the halted state. If information-erasing steps are present, there are additional problems. These problems are illustrated in this paper by consideration of operators for two simple one-step processes and two simple Turing machines. In general the operators are not unitary and, if erasing steps are present, they are not even contraction operators. Various methods of extension or dilation to unitary operators are discussed. Here unitary power dilations are considered as a solution to these problems. It is seen that these dilations automatically provide a good solution to the initial- and final-state problems. For processes with erasing steps, recording steps must be included prior to the dilation, but only for the steps that erase information. Hamiltonians for these processes are also discussed. It is noted that H, described by exp(-iHΔ)=UT, where UT is a unitary step operator for the process and Δ a time interval, has complexity problems. These problems and those noted above are avoided here by the use of the Feynman approach to constructing Hamiltonians directly from the unitary power dilations of the model operators. It is seen that the Hamiltonians so constructed have some interesting properties
Compactifications of the Heterotic string with unitary bundles
Weigand, T.
2006-05-23
In this thesis we investigate a large new class of four-dimensional supersymmetric string vacua defined as compactifications of the E{sub 8} x E{sub 8} and the SO(32) heterotic string on smooth Calabi-Yau threefolds with unitary gauge bundles and heterotic five-branes. The first part of the thesis discusses the implementation of this idea into the E{sub 8} x E{sub 8} heterotic string. After specifying a large class of group theoretic embeddings featuring unitary bundles, we analyse the effective four-dimensional N=1 supergravity upon compactification. From the gauge invariant Kaehler potential for the moduli fields we derive a modification of the Fayet-Iliopoulos D-terms arising at one-loop in string perturbation theory. From this we conjecture a one-loop deformation of the Hermitian Yang-Mills equation and introduce the idea of {lambda}-stability as the perturbatively correct stability concept generalising the notion of Mumford stability valid at tree-level. We then proceed to a definition of SO(32) heterotic vacua with unitary gauge bundles in the presence of heterotic five-branes and find agreement of the resulting spectrum with the S-dual framework of Type I/Type IIB orientifolds. A similar analysis of the effective four-dimensional supergravity is performed. Further evidence for the proposed one-loop correction to the stability condition is found by identifying the heterotic corrections as the S-dual of the perturbative part of {pi}-stability as the correct stability concept in Type IIB theory. After reviewing the construction of holomorphic stable vector bundles on elliptically fibered Calabi-Yau manifolds via spectral covers, we provide semi-realistic examples for SO(32) heterotic vacua with Pati-Salam and MSSM-like gauge sectors. We finally discuss the construction of realistic vacua with flipped SU(5) GUT and MSSM gauge group within the E{sub 8} x E{sub 8} framework, based on the embedding of line bundles into both E{sub 8} factors. Some of the appealing
Magnetic moments of charm baryons in chiral perturbation theory
Magnetic moments of the charm baryons of the sextet and of the 3*-plet are re-evaluated in the framework of Heavy Hadron Chiral Perturbation Theory (HHCPT). NRQM and broken SU(4) unitary symmetry model are used to obtain tree-level magnetic moments. Calculations of a unitary symmetry part of one-loop contributions to magnetic moments of the charm baryons are performed in detail in terms of the SU(4) couplings of charm baryons to Goldstone bosons. The relations between the magnetic moments of the sextet 1/2 baryons with the one-loop corrections are shown to coincide with the NRQM relations. The correspondence between HHCPT results and those of NRQM and unitary symmetry model is discussed. It is shown that one-loop corrections can effectively be absorbed into the tree-level formulae for the magnetic moments of the charm baryons in the broken SU(4) unitary symmetry model and partially in the NRQM. (author)
Chirality has recently been proposed as a novel feature of rotating nuclei [1]. Because the chiral symmetry is dichotomic, its spontaneous breaking by the axial angular momentum vector leads to doublets of closely lying rotational bands of the same parity. To investigate nuclear chirality, next to establish the existence of almost degenerate rotational bands, it is necessary to measure also other observables and compare them to the model predictions. The crucial test for the suggested nuclei as candidates to express chirality is based on precise lifetime measurements. Two lifetime experiments and theoretical approaches for the description of the experimental results will be presented. Lifetimes of exited states in 134Pr were measured [2,3] by means of the recoil distance Doppler-shift and Doppler-shift attenuation techniques. The branching ratios and the electric or magnetic character of the transitions were also investigated [3]. The experiments were performed at IReS, Strasbourg, using the EUROBALL IV spectrometer, in conjunction with the inner bismuth germanate ball and the Cologne coincidence plunger apparatus. Exited states in 134Pr were populated in the fusion-evaporation reaction 119Sn(19F, 4n)134Pr. The possible chiral interpretation of twin bands was investigated in the two-quasiparticle triaxial rotor [1] and interacting boson-fermion-fermion models [4]. Both theoretical approaches can describe the level-scheme of 134Pr. The analysis of the wave functions has shown that the possibility for the angular momenta of the proton, neutron, and core to find themselves in the favorable, almost orthogonal geometry, is present but is far from being dominant [3,5]. The structure is characterized by large β and γ fluctuations. The existence of doublets of bands in 134Pr can be attributed to weak chirality dominated by shape fluctuations. In a second experiment branching ratios and lifetimes in 136Pm were measured by means of the recoil distance Doppler-shift and
Testing the Unitary and Nash Bargaining Household Models in India
T. Lakshmanasamy
2003-01-01
This paper tests the unitary or common preference approach versus the collective models of household behaviour in India. Using the independent female unearned income as an indicator of female’s control over resources within the household in the bargaining strategy, we study the effect of pooled unearned income versus independent unearned income of the spouses on five household decisions, viz., male and female labour supply, household expenditures on food, education and health. The OLS estimat...
Crypto-Unitary Forms of Quantum Evolution Operators
Znojil, Miloslav
2013-06-01
The description of quantum evolution using unitary operator {u}(t)=exp(-i{h}t) requires that the underlying self-adjoint quantum Hamiltonian {h} remains time-independent. In a way extending the so called {PT}-symmetric quantum mechanics to the models with manifestly time-dependent "charge" {C}(t) we propose and describe an extension of such an exponential-operator approach to evolution to the manifestly time-dependent self-adjoint quantum Hamiltonians {h}(t).
Floss, H.G. [Univ. of Washington, Seattle, WA (United States)
1994-12-01
This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.
Unitary groups and spectral sets
Dutkay, Dorin Ervin
2012-01-01
We study spectral theory for bounded Borel subsets of $\\br$ and in particular finite unions of intervals. For Hilbert space, we take $L^2$ of the union of the intervals. This yields a boundary value problem arising from the minimal operator $\\Ds = \\frac1{2\\pi i}\\frac{d}{dx}$ with domain consisting of $C^\\infty$ functions vanishing at the endpoints. We offer a detailed interplay between geometric configurations of unions of intervals and a spectral theory for the corresponding selfadjoint extensions of $\\Ds$ and for the associated unitary groups of local translations. While motivated by scattering theory and quantum graphs, our present focus is on the Fuglede-spectral pair problem. Stated more generally, this problem asks for a determination of those bounded Borel sets $\\Omega$ in $\\br^k$ such that $L^2(\\Omega)$ has an orthogonal basis of Fourier frequencies (spectrum), i.e., a total set of orthogonal complex exponentials restricted to $\\Omega$. In the general case, we characterize Borel sets $\\Omega$ having t...
Intercept Capacity: Unknown Unitary Transformation
Bill Moran
2008-11-01
Full Text Available We consider the problem of intercepting communications signals between Multiple-Input Multiple-Output (MIMO communication systems. To correctly detect a transmitted message it is necessary to know the gain matrix that represents the channel between the transmitter and the receiver. However, even if the receiver has knowledge of the message symbol set, it may not be possible to estimate the channel matrix. Blind Source Separation (BSS techniques, such as Independent Component Analysis (ICA can go some way to extracting independent signals from individual transmission antennae but these may have been preprocessed in a manner unknown to the receiver. In this paper we consider the situation where a communications interception system has prior knowledge of the message symbol set, the channel matrix between the transmission system and the interception system and is able to resolve the transmissionss from independent antennae. The question then becomes: what is the mutual information available to the interceptor when an unknown unitary transformation matrix is employed by the transmitter.
An explicit family of unitaries with exponentially minimal length Pauli geodesics
Huang, Wei
2007-01-01
Recently, Nielsen et al have proposed a geometric approach to quantum computation. They've shown that the size of the minimum quantum circuits implementing a unitary U, up to polynomial factors, equals to the length of minimal geodesic from identity I through U. They've investigated a large class of solutions to the geodesic equation, called Pauli geodesics. They've raised a natural question whether we can explicitly construct a family of unitaries U that have exponentially long minimal lengt...
H Weigel
2003-11-01
In this talk I review studies of hadron properties in bosonized chiral quark models for the quark ﬂavor dynamics. Mesons are constructed from Bethe–Salpeter equations and baryons emerge as chiral solitons. Such models require regularization and I show that the two-fold Pauli–Villars regularization scheme not only fully regularizes the effective action but also leads the scaling laws for structure functions. For the nucleon structure functions the present approach serves to determine the regularization prescription for structure functions whose leading moments are not given by matrix elements of local operators. Some numerical results are presented for the spin structure functions.
Non-unitary probabilistic quantum computing
Gingrich, Robert M.; Williams, Colin P.
2004-01-01
We present a method for designing quantum circuits that perform non-unitary quantum computations on n-qubit states probabilistically, and give analytic expressions for the success probability and fidelity.
On some classes of bipartite unitary operators
Deschamps, Julien; Nechita, Ion; Pellegrini, Clément
2016-08-01
We investigate unitary operators acting on a tensor product space, with the property that the quantum channels they generate, via the Stinespring dilation theorem, are of a particular type, independently of the state of the ancilla system in the Stinespring relation. The types of quantum channels we consider are those of interest in quantum information theory: unitary conjugations, constant channels, unital channels, mixed unitary channels, positive partial transpose channels, and entanglement breaking channels. For some of the classes of bipartite unitary operators corresponding to the above types of channels, we provide explicit characterizations, necessary and/or sufficient conditions for membership, and we compute the dimension of the corresponding algebraic variety. Inclusions between these classes are considered, and we show that for small dimensions, many of these sets are identical.
Entanglement quantification by local unitary operations
Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitary operations play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as ''mirror entanglement.'' They are constructed by first considering the (squared) Hilbert-Schmidt distance of the state from the set of states obtained by applying to it a given local unitary operator. To the action of each different local unitary operator there corresponds a different distance. We then minimize these distances over the sets of local unitary operations with different spectra, obtaining an entire family of different entanglement monotones. We show that these mirror-entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary operator for the associated mirror entanglement to be faithful, i.e., to vanish in and only in separable pure states. We analyze in detail the properties of one particularly relevant member of the family, the ''stellar mirror entanglement'' associated with the traceless local unitary operations with nondegenerate spectra and equispaced eigenvalues in the complex plane. This particular measure generalizes the original analysis of S. M. Giampaolo and F. Illuminati [Phys. Rev. A 76, 042301 (2007)], valid for qubits and qutrits. We prove that the stellar entanglement is a faithful bipartite entanglement monotone in any dimension and that it is bounded from below by a function proportional to the linear entropy and from above by the linear entropy itself, coinciding with it in two- and three-dimensional spaces.
Uncertainty Relations for General Unitary Operators
Bagchi, Shrobona; Pati, Arun Kumar
2015-01-01
We derive several uncertainty relations for two arbitrary unitary operators acting on physical states of any Hilbert space (finite or infinite dimensional). We show that our bounds are tighter in various cases than the ones existing in the current literature. With regard to the minimum uncertainty state for the cases of both the finite as well as the infinite dimensional unitary operators, we derive the minimum uncertainty state equation by the analytic method. As an application of this, we f...
Entanglement quantification by local unitary operations
Monras, A.; Giampaolo, S. M.; Gualdi, G.; Illuminati, F. [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, CNISM, Unita di Salerno, and INFN, Sezione di Napoli-Gruppo Collegato di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy); Adesso, G.; Davies, G. B. [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)
2011-07-15
Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitary operations play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as ''mirror entanglement.'' They are constructed by first considering the (squared) Hilbert-Schmidt distance of the state from the set of states obtained by applying to it a given local unitary operator. To the action of each different local unitary operator there corresponds a different distance. We then minimize these distances over the sets of local unitary operations with different spectra, obtaining an entire family of different entanglement monotones. We show that these mirror-entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary operator for the associated mirror entanglement to be faithful, i.e., to vanish in and only in separable pure states. We analyze in detail the properties of one particularly relevant member of the family, the ''stellar mirror entanglement'' associated with the traceless local unitary operations with nondegenerate spectra and equispaced eigenvalues in the complex plane. This particular measure generalizes the original analysis of S. M. Giampaolo and F. Illuminati [Phys. Rev. A 76, 042301 (2007)], valid for qubits and qutrits. We prove that the stellar entanglement is a faithful bipartite entanglement monotone in any dimension and that it is bounded from below by a function proportional to the linear entropy and from above by the linear entropy itself, coinciding with it in two- and three-dimensional spaces.
Entanglement quantification by local unitary operations
Monras, A.; Adesso, G.; Giampaolo, S. M.; Gualdi, G.; Davies, G. B.; Illuminati, F.
2011-07-01
Invariance under local unitary operations is a fundamental property that must be obeyed by every proper measure of quantum entanglement. However, this is not the only aspect of entanglement theory where local unitary operations play a relevant role. In the present work we show that the application of suitable local unitary operations defines a family of bipartite entanglement monotones, collectively referred to as “mirror entanglement.” They are constructed by first considering the (squared) Hilbert-Schmidt distance of the state from the set of states obtained by applying to it a given local unitary operator. To the action of each different local unitary operator there corresponds a different distance. We then minimize these distances over the sets of local unitary operations with different spectra, obtaining an entire family of different entanglement monotones. We show that these mirror-entanglement monotones are organized in a hierarchical structure, and we establish the conditions that need to be imposed on the spectrum of a local unitary operator for the associated mirror entanglement to be faithful, i.e., to vanish in and only in separable pure states. We analyze in detail the properties of one particularly relevant member of the family, the “stellar mirror entanglement” associated with the traceless local unitary operations with nondegenerate spectra and equispaced eigenvalues in the complex plane. This particular measure generalizes the original analysis of S. M. Giampaolo and F. Illuminati [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.76.042301 76, 042301 (2007)], valid for qubits and qutrits. We prove that the stellar entanglement is a faithful bipartite entanglement monotone in any dimension and that it is bounded from below by a function proportional to the linear entropy and from above by the linear entropy itself, coinciding with it in two- and three-dimensional spaces.
Quantum state engineering via unitary transformations
Vidiella-Barranco, A.; Roversi, J. A.
1998-01-01
We construct a Hamiltonian for the generation of arbitrary pure states of the quantized electromagnetic field. The proposition is based upon the fact that a unitary transformation for the generation of number states has been already found. The general unitary transformation here obtained, would allow the use of nonlinear interactions for the production of pure states. We discuss the applicability of this method by giving examples of generation of simple superposition states. We also compare o...
Mass-Selective Chiral Analysis.
Boesl, Ulrich; Kartouzian, Aras
2016-06-12
Three ways of realizing mass-selective chiral analysis are reviewed. The first is based on the formation of diastereomers that are of homo- and hetero- type with respect to the enantiomers of involved chiral molecules. This way is quite well-established with numerous applications. The other two ways are more recent developments, both based on circular dichroism (CD). In one, conventional or nonlinear electronic CD is linked to mass spectrometry (MS) by resonance-enhanced multiphoton ionization. The other is based on CD in the angular distribution of photoelectrons, which is measured in combination with MS via photoion photoelectron coincidence. Among the many important applications of mass-selective chiral analysis, this review focuses on its use as an analytical tool for the development of heterogeneous enantioselective chemical catalysis. There exist other approaches to combine chiral analysis and mass-selective detection, such as chiral chromatography MS, which are not discussed here. PMID:27070181
Mass-Selective Chiral Analysis
Boesl, Ulrich; Kartouzian, Aras
2016-06-01
Three ways of realizing mass-selective chiral analysis are reviewed. The first is based on the formation of diastereomers that are of homo- and hetero- type with respect to the enantiomers of involved chiral molecules. This way is quite well-established with numerous applications. The other two ways are more recent developments, both based on circular dichroism (CD). In one, conventional or nonlinear electronic CD is linked to mass spectrometry (MS) by resonance-enhanced multiphoton ionization. The other is based on CD in the angular distribution of photoelectrons, which is measured in combination with MS via photoion photoelectron coincidence. Among the many important applications of mass-selective chiral analysis, this review focuses on its use as an analytical tool for the development of heterogeneous enantioselective chemical catalysis. There exist other approaches to combine chiral analysis and mass-selective detection, such as chiral chromatography MS, which are not discussed here.
Liu, Zhaosen; Ian, Hou
2016-04-01
We employed a quantum simulation approach to investigate the magnetic properties of monolayer square nanodisks with Dzyaloshinsky-Moriya (DM) interaction. The computational program converged very quickly, and generated chiral spin structures on the disk planes with good symmetry. When the DM interaction is sufficiently strong, multi-domain structures appears, their sizes or average distance between each pair of domains can be approximately described by a modified grid theory. We further found that the external magnetic field and uniaxial magnetic anisotropy both normal to the disk plane lead to reductions of the total free energy and total energy of the nanosystems, thus are able to stabilize and/or induce the vortical structures, however, the chirality of the vortex is still determined by the sign of the DM interaction parameter. Moreover, the geometric shape of the nanodisk affects the spin configuration on the disk plane as well.
Single-qubit unitary gates by graph scattering
Blumer, Benjamin A; Feder, David L
2011-01-01
We consider the effects of plane-wave states scattering off finite graphs, as an approach to implementing single-qubit unitary operations within the continuous-time quantum walk framework of universal quantum computation. Four semi-infinite tails are attached at arbitrary points of a given graph, representing the input and output registers of a single qubit. For a range of momentum eigenstates, we enumerate all of the graphs with up to $n=9$ vertices for which the scattering implements a single-qubit gate. As $n$ increases, the number of new unitary operations increases exponentially, and for $n>6$ the majority correspond to rotations about axes distributed roughly uniformly across the Bloch sphere. Rotations by both rational and irrational multiples of $\\pi$ are found.
Optimal quantum learning of a unitary transformation
We address the problem of learning an unknown unitary transformation from a finite number of examples. The problem consists in finding the learning machine that optimally emulates the examples, thus reproducing the unknown unitary with maximum fidelity. Learning a unitary is equivalent to storing it in the state of a quantum memory (the memory of the learning machine) and subsequently retrieving it. We prove that, whenever the unknown unitary is drawn from a group, the optimal strategy consists in a parallel call of the available uses followed by a 'measure-and-rotate' retrieving. Differing from the case of quantum cloning, where the incoherent 'measure-and-prepare' strategies are typically suboptimal, in the case of learning the 'measure-and-rotate' strategy is optimal even when the learning machine is asked to reproduce a single copy of the unknown unitary. We finally address the problem of the optimal inversion of an unknown unitary evolution, showing also in this case the optimality of the 'measure-and-rotate' strategies and applying our result to the optimal approximate realignment of reference frames for quantum communication.
Daskin, Anmer; Kais, Sabre
2011-04-14
Constructing appropriate unitary matrix operators for new quantum algorithms and finding the minimum cost gate sequences for the implementation of these unitary operators is of fundamental importance in the field of quantum information and quantum computation. Evolution of quantum circuits faces two major challenges: complex and huge search space and the high costs of simulating quantum circuits on classical computers. Here, we use the group leaders optimization algorithm to decompose a given unitary matrix into a proper-minimum cost quantum gate sequence. We test the method on the known decompositions of Toffoli gate, the amplification step of the Grover search algorithm, the quantum Fourier transform, and the sender part of the quantum teleportation. Using this procedure, we present the circuit designs for the simulation of the unitary propagators of the Hamiltonians for the hydrogen and the water molecules. The approach is general and can be applied to generate the sequence of quantum gates for larger molecular systems. PMID:21495747
Asymptotic expansions for the Gaussian unitary ensemble
Haagerup, Uffe; Thorbjørnsen, Steen
2012-01-01
Let g : R ¿ C be a C8-function with all derivatives bounded and let trn denote the normalized trace on the n × n matrices. In Ref. 3 Ercolani and McLaughlin established asymptotic expansions of the mean value ¿{trn(g(Xn))} for a rather general class of random matrices Xn, including the Gaussian...... Unitary Ensemble (GUE). Using an analytical approach, we provide in the present paper an alternative proof of this asymptotic expansion in the GUE case. Specifically we derive for a random matrix Xn that where k is an arbitrary positive integer. Considered as mappings of g, we determine the coefficients...... aj(g), j ¿ N, as distributions (in the sense of L. Schwarts). We derive a similar asymptotic expansion for the covariance Cov{Trn[f(Xn)], Trn[g(Xn)]}, where f is a function of the same kind as g, and Trn = n trn. Special focus is drawn to the case where and for ¿, µ in C\\R. In this case the mean and...
Harmonic-oscillator pattern arising from an algebraic approach to chiral symmetry
Buccella, F; Savoy, C A
1972-01-01
The Weinberg equation for the (mass)/sup 2/ operator (Q/sub 5//sup +/, (Q/sub 5//sup +/, m/sup 2/))=0, between meson states, is saturated in a perturbative approach. The generator Z of the mixing operators is completely established as Z=(W*M)/sub z/, where W is the W-spin operator and M is the co-ordinate of the three-dimensional harmonic oscillator. In a perturbative expansion of the (mass)/sup 2/ operator, the lowest term consists of two parts, the harmonic-oscillator energy and a spin-orbit coupling of the form (-1)/sup L+1/(L.S+/sup 1///sub 2 /). The resulting (mass)/sup 2/ consists of families of equispaced linearly rising trajectories. (11 refs).
Gleiser, Marcelo; Thorarinson, Joel; Walker, Sara Imari
2008-12-01
Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively L-amino acids, while only D-sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high intensity and long duration events may drive achiral initial conditions towards chirality. We argue that life’s homochirality resulted from sequential chiral symmetry breaking triggered by environmental events, thus extending the theory of punctuated equilibrium to the prebiotic realm. Applying our arguments to other potentially life-bearing planetary platforms, we predict that a statistically representative sampling will be racemic on average.
Gleiser, Marcelo; Walker, Sara Imari
2008-01-01
Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively levorotatory (L) amino acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high intensity and long duration events may drive achiral initial conditions towards chirality. We argue that life's homochirality resulted from sequential chiral symmetry breaking triggered by environmental events, thus extending the theory of punctuated equilibrium to the prebiotic realm. Applying our arguments to other potentially life-bearing planetary platforms, we predict that a statistically representative sampling will be racemic on average.
Chang, N P
1994-01-01
Chiral symmetry undergoes a metamorphosis at T.sub(c). For T < T.sub(c), the usual Noether charge, \\Qa, is dynamically broken by the vacuum. Above T.sub(c), chiral symmetry undergoes a subtle change, and the Noether charge \\underline{{\\em morphs}} into \\Qbeta, with the thermal vacuum now becoming invariant under \\Qbeta. This vacuum is however not invariant under the old \\Qa transformations. As a result, the pion remains strictly massless at high T. The pion propagates in the early universe with a halo. New order parameters are proposed to probe the structure of the new thermal vacuum.
Color transparency is the vanishing of initial and final state interactions, predicted by QCD to occur in high momentum transfer quasielastic nuclear reactions. For specific reactions involving nucleons, the initial and final state interactions are expected to be dominated by exchanges of pions. We argue that these interactions are also suppressed in high momentum transfer nuclear quasielastic reactions; this is open-quotes chiral transparency.close quotes We show that studies of the e3He→e'Δ++nn reaction could reveal the influence of chiral transparency. copyright 1997 The American Physical Society
Ding, Fei; Li, Xiu-Nan; Diao, Jian-Xiong; Sun, Ye; Zhang, Li; Sun, Ying
2012-06-01
Metalaxyl is an acylamine fungicide, belonging to the most widely known member of the amide group. This task is aimed to scrutinize binding region and spatial structural change of principal vector human serum albumin (HSA) complex with (R)-/(S)-metalaxyl by exploiting molecular modeling, steady-state and time-resolved fluorescence, and circular dichroism (CD) approaches. According to molecular modeling, (R)-metalaxyl is situated within subdomains IIA and IIIA and the affinity of site I with (R)-metalaxyl is greater than site II, whereas (S)-metalaxyl is only located at subdomain IIA and the affinity of (S)-metalaxyl with site I is superior compared with that with (R)-metalaxyl. This coincides with the competitive ligand binding, guanidine hydrochloride-induced unfolding of protein, and hydrophobic 8-anilino-1-naphthalenesulfonic acid experiments; the acting forces between (R)-/(S)-metalaxyl and HSA are hydrophobic, π-π interactions, and hydrogen bonds, as derived from molecular modeling. Fluorescence emission manifested that the complex of (R)-/(S)-metalaxyl to HSA is the formation of adduct with an affinity of 10(4) M(-1), which corroborates the time-resolved fluorescence that the static type was operated. Furthermore, the changes of far-UV CD spectra evidence the polypeptide chain of HSA partially unfolded after conjugation with (R)-/(S)-metalaxyl. Through this work, we envisage that it can offer central clues on the biodistribution, absorption, and bioaccumulation of (R)-/(S)-metalaxyl. PMID:22544615
Quarks, baryons and chiral symmetry
Hosaka, Atsushi
2001-01-01
This book describes baryon models constructed from quarks, mesons and chiral symmetry. The role of chiral symmetry and of quark model structure with SU(6) spin-flavor symmetry are discussed in detail, starting from a pedagogic introduction. Emphasis is placed on symmetry aspects of the theories. As an application, the chiral bag model is studied for nucleon structure, where important methods of theoretical physics, mostly related to the semiclassical approach for a system of strong interactions, are demonstrated. The text is more practical than formal; tools and ideas are explained in detail w
Chiral Nanoscience and Nanotechnology
Dibyendu S. Bag; T.C. Shami; K.U. Bhasker Rao
2008-01-01
The paper reviews nanoscale science and technology of chiral molecules/macromolecules-under twosubtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses thenanotechnology, where molecular chirality plays a role in the properties of materials, including molecularswitches, molecular motors, and other molecular devices; chiral supramolecules and self-assembled nanotubesand their functions are also highlighted. Nano-chiral technology describes the nanoscale appr...
Multiscale differential phase contrast analysis with a unitary detector
Lopatin, Sergei
2015-12-30
A new approach to generate differential phase contrast (DPC) images for the visualization and quantification of local magnetic fields in a wide range of modern nano materials is reported. In contrast to conventional DPC methods our technique utilizes the idea of a unitary detector under bright field conditions, making it immediately usable by a majority of modern transmission electron microscopes. The approach is put on test to characterize the local magnetization of cylindrical nanowires and their 3D ordered arrays, revealing high sensitivity of our method in a combination with nanometer-scale spatial resolution.
We present many varied chiral symmetry models at the quark level which consistently describe strong interaction hadron dynamics. The pattern that emerges is a nonstrange current quark mass scale mcur ≅ (34-69) MeV and a current quark mass ratio (ms/m)cur ≅ 5-6 along with no strange quark content in nucleons. (orig./WL)
Developing a Practical Chiral Toolbox for Asymmetric Catalytic Reactions
ZHANG; XuMu
2001-01-01
Chiral Quest's Toolbox Approach: During the last several decades, chemists have made major progress in discovering man-made catalysts to perform challenging asymmetric transformations. However, there is no universal chiral ligand or catalyst for solving problems in enantioselective transformations. The focus of Chiral Quest's research is to develop a useful chiral toolbox for strategically important asymmetric catalytic reactions by inventing a diverse set of novel chiral ligands and combining them with transition metals as effective enantioselective catalysts. The toolbox approach addresses significant problems in organic stereochemistry and has resulted in practical methods for the synthesis of chiral pharmaceuticals and agrochemicals ……
Developing a Practical Chiral Toolbox for Asymmetric Catalytic Reactions
ZHANG XuMu
2001-01-01
@@ Chiral Quest's Toolbox Approach: During the last several decades, chemists have made major progress in discovering man-made catalysts to perform challenging asymmetric transformations. However, there is no universal chiral ligand or catalyst for solving problems in enantioselective transformations. The focus of Chiral Quest's research is to develop a useful chiral toolbox for strategically important asymmetric catalytic reactions by inventing a diverse set of novel chiral ligands and combining them with transition metals as effective enantioselective catalysts. The toolbox approach addresses significant problems in organic stereochemistry and has resulted in practical methods for the synthesis of chiral pharmaceuticals and agrochemicals
Chiral perturbation theory with nucleons
I review the constraints posed on the interactions of pions, nucleons and photons by the spontaneously broken chiral symmetry of QCD. The framework to perform these calculations, chiral perturbation theory, is briefly discussed in the meson sector. The method is a simultaneous expansion of the Greens functions in powers of external moments and quark masses around the massless case, the chiral limit. To perform this expansion, use is made of a phenomenological Lagrangian which encodes the Ward-identities and pertinent symmetries of QCD. The concept of chiral power counting is introduced. The main part of the lectures of consists in describing how to include baryons (nucleons) and how the chiral structure is modified by the fact that the nucleon mass in the chiral limit does not vanish. Particular emphasis is put on working out applications to show the strengths and limitations of the methods. Some processes which are discussed are threshold photopion production, low-energy compton scattering off nucleons, πN scattering and the σ-term. The implications of the broken chiral symmetry on the nuclear forces are briefly described. An alternative approach, in which the baryons are treated as very heavy fields, is touched upon
Generalized Unitaries and the Picard Group
Skeide, M.
2005-01-01
After discussing some basic facts about generalized module maps, we use the representation theory of the algebra of adjointable operators on a Hilbert B-module E to show that the quotient of the group of generalized unitaries on E and its normal subgroup of unitaries on E is a subgroup of the group of automorphisms of the range ideal of E in B. We determine the kernel of the canonical mapping into the Picard group of the range ideal in terms of the group of its quasi inner automorphisms. As a...
Unitary Multiperfect Numbers in Certain Quadratic Rings
Defant, Colin
2014-01-01
A unitary divisor $c$ of a positive integer $n$ is a positive divisor of $n$ that is relatively prime to $\\displaystyle{\\frac{n}{c}}$. For any integer $k$, the function $\\sigma_k^*$ is a multiplicative arithmetic function defined so that $\\sigma_k^*(n)$ is the sum of the $k^{th}$ powers of the unitary divisors of $n$. We provide analogues of the functions $\\sigma_k^*$ in imaginary quadratic rings that are unique factorization domains. We then explore properties of what we call $n$-powerfully ...
Unified models and unitary symmetry
The experimentally established small size of the space time region where weak interactions occur; ''the weak beg'', is taken as a starting point for a dynamical model for parity violation in weak interactions. It is argued that weakly interacting Dirac bi-spinors behave as massles in the weak beg, and then they split into pairs of decoupled Weyl spinors. As a consequence, any P, C, T conserving gauge Lagrangian in terms of multiplets of Dirac fields will split, in the weak bag, into P and C violating terms representing the weak interactions of the concerned fermions. Following the criterion of maximal simplicity and economy, some SU(N), U(N) symmetruc models are presented. It is shown that (a) Reduction of SU(3) x P, C, T symmetry to SU(2) x U(1) x PC, T for weak interactions is easily obtained by force of chiral projectors. (b) The models are apt to represent all weak and e.m. properties of known leptons and a unified model for weak and e.m. interactions, generalization of the Salam-Weinberg model, emerges with the mixing angle theta depending on N in SU(N). For N=3 the model coincides with the Salam-Weinberg model with theta=30sup(deg). At present experimental data seem to favour the SU(4) model where sin sup(2)theta = 1/3. (c) Absence of ΔS=1 neutral currents can easily be explained already in the frame of SU(3). (d) Integer charges for leptons and fractional charges for quarks can be fitted in appropriate SU(3)-U(3) models. (e) In U(N) symmetric models the resulting q.e.d. presents Pauli-Villars regularization of the self-energy and vertex parts, and the Schwinger-Dyson equations for self-masses are of the Fredholm type as a consequence of the U(N) symmetry and of the neutral currents. The possibility then arises of a full q.e.d. regularization by weak interactions. (f) Neutral current interactions are parity conserving (axial) among charged particles, while parity violating among neutral-charged, neutral-neutral ones in all models presented. A generalized
Gleiser, Marcelo; Thorarinson, Joel; Walker, Sara Imari
2008-01-01
Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively levorotatory (L) amino acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high int...
Aznauryan, I. G.
2002-01-01
Two approaches for analysis of pion photo- and electroproduction on nucleons in the resonance energy region are checked at $Q^2=0$ using the results of GWU(VPI) partial-wave analysis of photoproduction data. The approaches are based on dispersion relations and unitary isobar model. Within dispersion relations good description of photoproduction multipoles is obtained up to $W=1.8 GeV$. Within unitary isobar model, modified with increasing energy by incorporation of Regge poles, and with unifi...
Zou, Dandan; Cao, Xin [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Lu, Xinpei, E-mail: luxinpei@hotmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Ostrikov, Kostya [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4000 (Australia); Comonwealth Scientific and Industrial Research Organization, P.O. Box 218, Sydney, New South Wales 2070 (Australia)
2015-10-15
The interaction of time-varying electromagnetic fields and solid, liquid, and gaseous matter may lead to electrical breakdown phenomena through the excitation of ionization waves or streamers that control the dynamics of localized plasma propagation through the media. The streamers usually propagate along straight lines, either between random points in space or along a certain direction in a guided mode. Here, we report on a new type of plasma discharges with the regular helical propagation pattern driven by a pulsed dc voltage in nitrogen at sub-atmospheric-pressure conditions. The helical guided streamers, named chiral streamers or chi-streamers, are excited without any external magnetic fields, which commonly cause helical plasma motions. We also demonstrate a hybrid propagation mode involving the interchangeable chiral streamers and the straight-line propagating plasmas. High-speed, time-resolved optical imaging reveals that the chiral streamers and the hybrid patterns are made of spatially localized discrete plasma bullets, similar to the straight-line guided streamers. These results may enable effective control of propagation of confined plasmas and electromagnetic energy along pre-determined, potentially deterministic paths, which have important implications for the development of next-generation plasma-based radiation sources, communication devices, and medical treatments.
Zou, Dandan; Cao, Xin; Lu, Xinpei; Ostrikov, Kostya Ken
2015-10-01
The interaction of time-varying electromagnetic fields and solid, liquid, and gaseous matter may lead to electrical breakdown phenomena through the excitation of ionization waves or streamers that control the dynamics of localized plasma propagation through the media. The streamers usually propagate along straight lines, either between random points in space or along a certain direction in a guided mode. Here, we report on a new type of plasma discharges with the regular helical propagation pattern driven by a pulsed dc voltage in nitrogen at sub-atmospheric-pressure conditions. The helical guided streamers, named chiral streamers or chi-streamers, are excited without any external magnetic fields, which commonly cause helical plasma motions. We also demonstrate a hybrid propagation mode involving the interchangeable chiral streamers and the straight-line propagating plasmas. High-speed, time-resolved optical imaging reveals that the chiral streamers and the hybrid patterns are made of spatially localized discrete plasma bullets, similar to the straight-line guided streamers. These results may enable effective control of propagation of confined plasmas and electromagnetic energy along pre-determined, potentially deterministic paths, which have important implications for the development of next-generation plasma-based radiation sources, communication devices, and medical treatments.
Quantum Systems and Alternative Unitary Descriptions
Marmo, G; Ventriglia, F
2003-01-01
Motivated by the existence of bi-Hamiltonian classical systems and the correspondence principle, in this paper we analyze the problem of finding Hermitian scalar products which turn a given flow on a Hilbert space into a unitary one. We show how different invariant Hermitian scalar products give rise to different descriptions of a quantum system in the Ehrenfest and Heisenberg picture.
Developmental Dyspraxia: Is It a Unitary Function?
Ayres, A. Jean; And Others
1987-01-01
A group of 182 children (ages four through nine) with known or suspected sensory integrative dysfunction were assessed using tests and clinical observations to examine developmental dyspraxia. The study did not justify the existence of either a unitary function or different types of developmental dyspraxia. (Author/CH)
Unitary information ether and its possible applications
The idea of information ether as the unitary information field is developed. It rests on the assumption that the notion of information is a fundamental category in the description of reality and that it can be defined independently from the notion of probability itself. It is shown that the information ether provides a deterministic background for the nonlinear wave hypothesis and quantum cybernetics. (orig.)
Spin squeezing criterion with local unitary invariance
Devi, A R U; Sanders, B C
2003-01-01
We propose a new spin squeezing criterion for arbitrary multi-qubit states that is invariant under local unitary operations. We find that, for arbitrary pure two-qubit states, spin squeezing is equivalent to entanglement, and multi-qubit states are entangled if this new spin squeezing parameter is less than 1.
Chiral geometry in multiple chiral doublet bands
Zhang, Hao
2015-01-01
The chiral geometry of the multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters $\\gamma$ in the particle rotor model with $\\pi h_{11/2}\\otimes \
Asymmetric synthesis using chiral-encoded metal.
Yutthalekha, Thittaya; Wattanakit, Chularat; Lapeyre, Veronique; Nokbin, Somkiat; Warakulwit, Chompunuch; Limtrakul, Jumras; Kuhn, Alexander
2016-01-01
The synthesis of chiral compounds is of crucial importance in many areas of society and science, including medicine, biology, chemistry, biotechnology and agriculture. Thus, there is a fundamental interest in developing new approaches for the selective production of enantiomers. Here we report the use of mesoporous metal structures with encoded geometric chiral information for inducing asymmetry in the electrochemical synthesis of mandelic acid as a model molecule. The chiral-encoded mesoporous metal, obtained by the electrochemical reduction of platinum salts in the presence of a liquid crystal phase and the chiral template molecule, perfectly retains the chiral information after removal of the template. Starting from a prochiral compound we demonstrate enantiomeric excess of the (R)-enantiomer when using (R)-imprinted electrodes and vice versa for the (S)-imprinted ones. Moreover, changing the amount of chiral cavities in the material allows tuning the enantioselectivity. PMID:27562028
Mishra, H
2001-01-01
We discuss in this note simultaneous existence of chiral symmetry breaking and color superconductivity at finite temperature and density in a Nambu-Jona-Lasinio type model. The methodology involves an explicit construction of a variational ground state and minimisation of the thermodynamic potential. There exist nontrivial solutions to the gap equations at finite densities with both quark-antiquark as well as diquark condensates for the 'ground' state. However, such a phase is thermodynamically unstable with the pressure being negative in this region. We also compute the equation of state, and obtain the structure of the phase diagram in the model.
Hypernucleus-16O in the density-dependent Hartree approach based on the chiral-σ model
A relativistic density-dependent interaction has been used to study hypernucleus 16O. The density-dependent coupling constants of the relativistic effective Hartree-Lagrangian are obtained from the relativistic Brueckner-Bethe-Goldstone results of nuclear matter in the chiral-σ model. With these density-dependent coupling constants, the bound states and the single-particle energy spectra of the hypernuclei Λ16O and Σ16O are obtained. The theoretical results of Λ16O are in agreement with the experimental data fairly well
Universal structure and universal equations (PDE) for unitary ensembles
Rumanov, Igor
2010-08-01
Random matrix ensembles with unitary invariance of measure (UE) are described in a unified way using a combination of Tracy-Widom (TW) and Adler-Shiota-van Moerbeke approaches to the derivation of partial differential equations (PDEs) for spectral gap probabilities. First, general three-term recurrence relations for UE restricted to subsets of real line, or, in other words, for functions in the resolvent kernel, are obtained. Using them, simple universal relations between all TW dependent variables and one-dimensional Toda lattice τ-functions are found. A universal system of PDE for UE is derived from previous relations, which leads also to a single independent PDE for spectral gap probability of various UE. Thus, orthogonal function bases and Toda lattice are seen at the core of correspondence of different approaches. Moreover, Toda-AKNS system provides a common structure of PDE for unitary ensembles. Interestingly, this structure can be seen in two very different forms: one arises from orthogonal function-Toda lattice considerations, while the other comes from Schlesinger equations for isomonodromic deformations and their relation to TW equations. The simple example of Gaussian matrices most neatly exposes this structure.
Universal Structure and Universal PDE for Unitary Ensembles
Rumanov, Igor
2009-01-01
An attempt is made to describe random matrix ensembles with unitary invariance of measure (UE) in a unified way, using a combination of Tracy-Widom (TW) and Adler-Shiota-Van Moerbeke (ASvM) approaches to derivation of partial differential equations (PDE) for spectral gap probabilities. First, general 3-term recurrence relations for UE restricted to subsets of real line, or, in other words, for functions in the resolvent kernel, are obtained. Using them, simple universal relations between all TW dependent variables and one-dimensional Toda lattice $\\tau$-functions are found. A universal system of PDE for UE is derived from previous relations, which leads also to a {\\it single independent PDE} for spectral gap probability of various UE. Thus, orthogonal function bases and Toda lattice are seen at the core of correspondence of different approaches. Moreover, Toda-AKNS system provides a common structure of PDE for unitary ensembles. Interestingly, this structure can be seen in two very different forms: one arises...
Unitary integration with operator splitting for weakly dissipative systems
Unitary integration is a numerical method that preserves the structure of the quantum Liouville equation by evolving the density via unitary transformations. Unitary integrators preserve the kinematic invariants cj=trρj (j=1,...,n) to all orders in the time step. Here we extend unitary integration to weakly dissipative systems. We apply the technique of operator splitting, using a unitary integrator for the Hamiltonian evolution and a conventional integrator for the dissipative piece. In this way, we guarantee that all dissipation and decoherence (variation of the cj) is due to the new non-Hamiltonian terms and not to any numerical artifacts. We illustrate the method with examples. (author)
Is chiral symmetry manifested in nuclear structure?
Furnstahl, R. J.; Schwenk, A
2010-01-01
Spontaneously broken chiral symmetry is an established property of low-energy quantum chromodynamics, but finding direct evidence for it from nuclear structure data is a difficult challenge. Indeed, phenomenologically successful energy-density functional approaches do not even have explicit pions. Are there smoking guns for chiral symmetry in nuclei?
Black Hole Thermodynamics Based on Unitary Evolutions
Feng, Yu-Lei
2015-01-01
In this paper, we try to construct black hole thermodynamics based on the fact that, the formation and evaporation of a black hole can be described by quantum unitary evolutions. First, we show that the Bekenstein-Hawking entropy $S_{BH}$ cannot be a Boltzmann or thermal entropy. To confirm this statement, we show that the original black hole's "first law" cannot be treated as the first law of thermodynamics formally, due to some missing metric perturbations caused by matter. Then, by including those (quantum) metric perturbations, we show that the black hole formation and evaporation can be described in a unitary manner effectively, through a quantum channel between the exterior and interior of the event horizon. In this way, the paradoxes of information loss and firewall can be resolved effectively. Finally, we show that black hole thermodynamics can be constructed in an ordinary way, by constructing statistical mechanics.
Transition from Poisson to circular unitary ensemble
Vinayak; Akhilesh Pandey
2009-09-01
Transitions to universality classes of random matrix ensembles have been useful in the study of weakly-broken symmetries in quantum chaotic systems. Transitions involving Poisson as the initial ensemble have been particularly interesting. The exact two-point correlation function was derived by one of the present authors for the Poisson to circular unitary ensemble (CUE) transition with uniform initial density. This is given in terms of a rescaled symmetry breaking parameter Λ. The same result was obtained for Poisson to Gaussian unitary ensemble (GUE) transition by Kunz and Shapiro, using the contour-integral method of Brezin and Hikami. We show that their method is applicable to Poisson to CUE transition with arbitrary initial density. Their method is also applicable to the more general ℓ CUE to CUE transition where CUE refers to the superposition of ℓ independent CUE spectra in arbitrary ratio.
Generalized Unitaries and the Picard Group
Michael Skeide
2006-11-01
After discussing some basic facts about generalized module maps, we use the representation theory of the algebra $\\mathscr{B}^a(E)$ of adjointable operators on a Hilbert $\\mathcal{B}$-module to show that the quotient of the group of generalized unitaries on and its normal subgroup of unitaries on is a subgroup of the group of automorphisms of the range ideal $\\mathcal{B}_E$ of in $\\mathcal{B}$. We determine the kernel of the canonical mapping into the Picard group of $\\mathcal{B}_E$ in terms of the group of quasi inner automorphisms of $\\mathcal{B}_E$. As a by-product we identify the group of bistrict automorphisms of the algebra of adjointable operators on modulo inner automorphisms as a subgroup of the (opposite of the) Picard group.
On unitary subsectors of polycritical gravities
Kleinschmidt, Axel; Virmani, Amitabh
2012-01-01
We study higher-derivative gravity theories in arbitrary space-time dimension d with a cosmological constant at their maximally critical points where the masses of all linearized perturbations vanish. These theories have been conjectured to be dual to logarithmic conformal field theories in the (d-1)-dimensional boundary of an AdS solution. We determine the structure of the linearized perturbations and their boundary fall-off behaviour. The linearized modes exhibit the expected Jordan block structure and their inner products are shown to be those of a non-unitary theory. We demonstrate the existence of consistent unitary truncations of the polycritical gravity theory at the linearized level for odd rank.
Recurrence for discrete time unitary evolutions
Grünbaum, F A; Werner, A H; Werner, R F
2012-01-01
We consider quantum dynamical systems specified by a unitary operator U and an initial state vector \\phi. In each step the unitary is followed by a projective measurement checking whether the system has returned to the initial state. We call the system recurrent if this eventually happens with probability one. We show that recurrence is equivalent to the absence of an absolutely continuous part from the spectral measure of U with respect to \\phi. We also show that in the recurrent case the expected first return time is an integer or infinite, for which we give a topological interpretation. A key role in our theory is played by the first arrival amplitudes, which turn out to be the (complex conjugated) Taylor coefficients of the Schur function of the spectral measure. On the one hand, this provides a direct dynamical interpretation of these coefficients; on the other hand it links our definition of first return times to a large body of mathematical literature.
One dimensional quantum walk with unitary noise
Shapira, D; Bracken, A J; Hackett, M; Shapira, Daniel; Biham, Ofer; Hackett, Michelle
2003-01-01
The effect of unitary noise on the discrete one-dimensional quantum walk is studied using computer simulations. For the noiseless quantum walk, starting at the origin (n=0) at time t=0, the position distribution Pt(n) at time t is very different from the Gaussian distribution obtained for the classical random walk. Furthermore, its standard deviation, sigma(t) scales as sigma(t) ~ t, unlike the classical random walk for which sigma(t) ~ sqrt{t}. It is shown that when the quantum walk is exposed to unitary noise, it exhibits a crossover from quantum behavior for short times to classical-like behavior for long times. The crossover time is found to be T ~ alpha^(-2) where alpha is the standard deviation of the noise.
Unitary and room air-conditioners
Christian, J.E.
1977-09-01
The scope of this technology evaluation on room and unitary air conditioners covers the initial investment and performance characteristics needed for estimating the operating cost of air conditioners installed in an ICES community. Cooling capacities of commercially available room air conditioners range from 4000 Btu/h to 36,000 Btu/h; unitary air conditioners cover a range from 6000 Btu/h to 135,000 Btu/h. The information presented is in a form useful to both the computer programmer in the construction of a computer simulation of the packaged air-conditioner's performance and to the design engineer, interested in selecting a suitably sized and designed packaged air conditioner.
Chiral heat wave and mixed waves in kinetic theory
Frenklakh, D
2016-01-01
We study collective excitations in hot rotating chiral media in presence of magnetic field in kinetic theory, namely Chiral Heat Wave and its' mixings with Chiral Vortical Wave and Chiral Magnetic Wave. Our results for velocities of these waves have slight alterations from those obtained earlier. We explain the origin of these alterations and also give the most general expressions for the velocities of all these waves in hydrodynamic approach.
Unitary representations and harmonic analysis an introduction
Sugiura, M
1990-01-01
The principal aim of this book is to give an introduction to harmonic analysis and the theory of unitary representations of Lie groups. The second edition has been brought up to date with a number of textual changes in each of the five chapters, a new appendix on Fatou''s theorem has been added in connection with the limits of discrete series, and the bibliography has been tripled in length.
Unitary correlation in nuclear reaction theory
Mukhamedzhanov, A. M.; Kadyrov, A. S.
2010-01-01
We prove that the amplitudes for the (d,p), (d,pn) and (e,e'p) reactions determining the asymptotic behavior of the exact scattering wave functions in the corresponding channels are invariant under unitary correlation operators while the spectroscopic factors are not. Moreover, the exact reaction amplitudes are not parametrized in terms of the spectroscopic factors and cannot provide a tool to determine the spectroscopic factors.
Classical limits of an extended unitary model
The paper studies the limiting cases of an extended unitary model and it is shown that rotational, vibrational and transition excitation spectra are generated depending on the parameters ratio. The limits concerned resemble, by some properties, the analogous limits of an interacting boson model, however, the physical nature of the two models is different. Their generality is caused by the group structure similarity. 31 refs.; 5 figs.; 6 tabs
Fiorilla, Salvatore; Weise, Wolfram
2011-01-01
We calculate the equation of state of nuclear matter for arbitrary isospin-asymmetry up to three loop order in the free energy density in the framework of in-medium chiral perturbation theory. In our approach 1\\pi- and 2\\pi-exchange dynamics with the inclusion of the \\Delta-isobar excitation as an explicit degree of freedom, corresponding to the long- and intermediate-range correlations, are treated explicitly. Few contact terms fixed to reproduce selected known properties of nuclear matter encode the short-distance physics. Two-body as well as three-body forces are systematically included. We find a critical temperature of about 15 MeV for symmetric nuclear matter. We investigate the dependence of the liquid-gas first-order phase transition on isospin-asymmetry. In the same chiral framework we calculate the chiral condensate of isospin-symmetric nuclear matter at finite temperatures. The contribution of the \\Delta-isobar excitation is essential for stabilizing the condensate. As a result, we find no indicati...
Chiral symmetry and chiral-symmetry breaking
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed
Bruff, Garreth Edward
1997-01-01
Sustainable development can be approached from many different perspectives. Whilst short, 'punchy' definitions have successfully communicated and popularised sustainable development, a detailed and meaningful application of the concept is much more problematic. In order to address the situation, this thesis investigates the potential of unitary development plans (UDPs) to operationalise sustainable development in the current political and economic context. The study utilises a ...
On some integrals over the U(N) unitary group and their large N limit
Zinn-Justin, P [Laboratoire de Physique Theorique et Modeles Statistiques, Universite Paris-Sud, Batiment 100, F-91405 Orsay Cedex (France); Zuber, J-B [Service de Physique Theorique de Saclay, CEA/DSM/SPhT, Unite de recherche associee au CNRS, CEA-Saclay, F-91191 Gif sur Yvette Cedex (France)
2003-03-28
The integral over the U(N) unitary group I = {integral} DU exp Tr AU BU{dagger} is re-examined. Various approaches and extensions are first reviewed. The second half of the paper deals with more recent developments: relation with integrable Toda lattice hierarchy, diagrammatic expansion and combinatorics, and what they teach us on the large N limit of log I.
Plum, Eric, E-mail: erp@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I., E-mail: niz@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378 (Singapore)
2015-06-01
Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media.
Chiral symmetry on the lattice
The author reviews some of the difficulties associated with chiral symmetry in the context of a lattice regulator. The author discusses the structure of Wilson Fermions when the hopping parameter is in the vicinity of its critical value. Here one flavor contrasts sharply with the case of more, where a residual chiral symmetry survives anomalies. The author briefly discusses the surface mode approach, the use of mirror Fermions to cancel anomalies, and finally speculates on the problems with lattice versions of the standard model
Chiral symmetry on the lattice
Creutz, M.
1994-11-01
The author reviews some of the difficulties associated with chiral symmetry in the context of a lattice regulator. The author discusses the structure of Wilson Fermions when the hopping parameter is in the vicinity of its critical value. Here one flavor contrasts sharply with the case of more, where a residual chiral symmetry survives anomalies. The author briefly discusses the surface mode approach, the use of mirror Fermions to cancel anomalies, and finally speculates on the problems with lattice versions of the standard model.
Oset, E; Sekihara, T; Torres, A Martinez; Khemchandani, K P; Bayar, M; Yamagata-Sekihara, J
2012-01-01
We review recent work concerning the $\\bar{K}N$ interaction and Faddeev equations with chiral dynamics which allow us to look at the $\\bar{K}NN$ from a different perspective and pay attention to problems that have been posed in previous studies on the subject. We show results which provide extra experimental evidence on the existence of two $\\Lambda(1405)$ states. We then show the findings of a recent approach to Faddeev equations using chiral unitary dynamics, where an explicit cancellation of the two body off shell amplitude with three body forces stemming from the same chiral Lagrangians takes place. This removal of the unphysical off shell part of the amplitudes is most welcome and renders the approach unambiguous, showing that only on shell two body amplitudes need to be used. With this information in mind we use an approximation to the Faddeev equations within the fixed center approximation to study the $\\bar{K}NN$ system, providing answers within this approximation to questions that have been brought b...
Water-soluble chiral metallopeptoids.
Baskin, Maria; Maayan, Galia
2015-09-01
Metal ions play a significant role in the activity of biological systems including catalysis, recognition and folding. Therefore, introducing metal ions into peptidomimetic oligomers is a potential way for creating biomimetic metal complexes toward applications in sensing, recognition, drug design and catalysis. Herein we report the design, synthesis and characterization of water-soluble chiral N-substituted glycine oligomers, "peptoids," with one and two distinct intramolecular binding sites for metal ions such as copper and cobalt. We demonstrate for the first time the incorporation of the chiral hydrophilic group (S)-(+)-1-methoxy-2-propylamine (Nsmp) within peptoid sequences, which provides both chirality and water solubility. Two peptoids, a heptamer, and a dodecamer bearing two and four 8-hydroxyquinoline (HQ) groups respectively as metal-binding ligands, were synthesized on solid support using the submonomer approach. Using UV-titrations and ESI-MS analysis we demonstrate the creation of a novel metallopeptoid bearing two metal ions in distinct binding sites via intramolecular chelation. Exciton couplet circular dichroism (ECCD) demonstrated chiral induction from the chiral non-helical peptoids to the metal centers. PMID:25969151
Unitary spinor methods in general relativity
An overview is presented of the structure and applications of spinor fields in three-dimensional (pseudo-) Riemannian manifolds. A systematic treatment is possible that is independent of metric signature, since a fairly general structure exists associated with unitary spinors. Algebraic and analytic properties of spinors, the Ricci identities and curvature spinor are discussed, followed by spinor adjugation as space reflection, and the SU(2) and SU(1,1) spin coefficients with some applications including space times with Killing symmetries, initial value formulation etc. (R.P.) 16 refs
New identities between unitary minimal Virasoro characters
Taormina, A. (Dept. of Mathematical Sciences, Univ. of Durham (United Kingdom))
1994-10-01
Two sets of identities between unitary minimal Virasoro characters at levels m = 3, 4, 5 are presented and proven. The first identity suggests a connection between the Ising and the tricritical Ising models since the m = 3 Virasoro characters are obtained as bilinears of m = 4 Virasoro characters. The second identity gives the tricritical Ising model characters as bilinears in the Ising model characters and the six combinations of m = 5 Virasoro characters which do not appear in the spectrum of the three state Potts model. The implication of these identities on the study of the branching rules of N = 4 superconformal characters into SU(2) x SU(2) characters is discussed. (orig.)
Quantum reading of unitary optical devices
Dall' Arno, Michele [Graduate School of Information Science, Nagoya University, Nagoya, 464-8601 (Japan); ICFO-Institut de Ciencies Fotoniques, E-08860 Castelldefels (Barcelona) (Spain); Quit Group, Dipartimento di Fisica, via Bassi 6, I-27100 Pavia (Italy); Bisio, Alessandro; D' Ariano, Giacomo Mauro [Quit Group, Dipartimento di Fisica, via Bassi 6, I-27100 Pavia, Italy and Istituto Nazionale di Fisica Nucleare, Gruppo IV, via Bassi 6, I-27100 Pavia (Italy)
2014-12-04
We address the problem of quantum reading of optical memories, namely the retrieving of classical information stored in the optical properties of a media with minimum energy. We present optimal strategies for ambiguous and unambiguous quantum reading of unitary optical memories, namely when one's task is to minimize the probability of errors in the retrieved information and when perfect retrieving of information is achieved probabilistically, respectively. A comparison of the optimal strategy with coherent probes and homodyne detection shows that the former saves orders of magnitude of energy when achieving the same performances. Experimental proposals for quantum reading which are feasible with present quantum optical technology are reported.
Quantum reading of unitary optical devices
We address the problem of quantum reading of optical memories, namely the retrieving of classical information stored in the optical properties of a media with minimum energy. We present optimal strategies for ambiguous and unambiguous quantum reading of unitary optical memories, namely when one's task is to minimize the probability of errors in the retrieved information and when perfect retrieving of information is achieved probabilistically, respectively. A comparison of the optimal strategy with coherent probes and homodyne detection shows that the former saves orders of magnitude of energy when achieving the same performances. Experimental proposals for quantum reading which are feasible with present quantum optical technology are reported
Unitary water-to-air heat pumps
Christian, J.E.
1977-10-01
Performance and cost functions for nine unitary water-to-air heat pumps ranging in nominal size from /sup 1///sub 2/ to 26 tons are presented in mathematical form for easy use in heat pump computer simulations. COPs at nominal water source temperature of 60/sup 0/F range from 2.5 to 3.4 during the heating cycle; during the cooling cycle EERs range from 8.33 to 9.09 with 85/sup 0/F entering water source temperatures. The COP and EER values do not include water source pumping power or any energy requirements associated with a central heat source and heat rejection equipment.
Chiral Gravitational Waves from Chiral Fermions
Anber, Mohamed M
2016-01-01
We report on a new mechanism that leads to the generation of primordial chiral gravitational waves, and hence, the violation of the parity symmetry in the Universe. We show that nonperturbative production of fermions with a definite helicity is accompanied by the generation of chiral gravitational waves. This is a generic and model-independent phenomenon that can occur during inflation, reheating and radiation eras, and can leave imprints in the cosmic microwave background polarization and may be observed in future ground- and space-based interferometers. We also discuss a specific model where chiral gravitational waves are generated via the production of light chiral fermions during pseudoscalar inflation.
Radiative meson decays in chiral perturbation theory
Radiative meson decays are a fertile field for chiral perturbation theory. Chiral symmetry together with gauge invariance yield stringent constraints on radiative decay amplitudes. In addition to predicting decay rates and spectra, the chiral approach allows for a unified description of CP violation in radiative K decays. The chiral viewpoint in the recent controversy over the magnitude of two-photon exchange in the decay KL→ π0e+e- is exposed. The radiative decay η→π0γγ is discussed as an intriguing case where the leading result of chiral perturbation theory seems to be too small by two orders of magnitude in rate. 32 refs., 3 figs. (Author)
Moduli spaces of unitary conformal field theories
We investigate various features of moduli spaces of unitary conformal field theories. A geometric characterization of rational toroidal conformal field theories in arbitrary dimensions is presented and discussed in relation to singular tori and those with complex multiplication. We study the moduli space M2 of unitary two-dimensional conformal field theories with central charge c = 2. All the 26 non-exceptional non-isolated irreducible components of M2 are constructed that may be obtained by an orbifold procedure from toroidal theories. The parameter spaces and partition functions are calculated explicitly. All multicritical points and lines are determined, such that all but three of these 26 components are directly or indirectly connected to the space of toroidal theories in M2. Relating our results to those by Dixon, Ginsparg, Harvey on the classification of c = 3/2 superconformal field theories, we give geometric interpretations to all non-isolated orbifolds discussed by them and correct their statements on multicritical points within the moduli space of c = 3/2 superconformal field theories. In the main part of this work, we investigate the moduli space M of N = (4, 4) superconformal field theories with central charge c = 6. After a slight emendation of its global description we give generic partition functions for models contained in M. We explicitly determine the locations of various known models in the component of M associated to K3 surfaces
Anomalous Chiral Superfluidity
Lublinsky, Michael(Physics Department, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel); Zahed, Ismail
2009-01-01
We discuss both the anomalous Cartan currents and the energy-momentum tensor in a left chiral theory with flavour anomalies as an effective theory for flavored chiral phonons in a chiral superfluid with the gauged Wess-Zumino-Witten term. In the mean-field (leading tadpole) approximation the anomalous Cartan currents and the energy momentum tensor take the form of constitutive currents in the chiral superfluid state. The pertinence of higher order corrections and the Adler-Bardeen theorem is ...
Introduction to chiral symmetry
These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. Effective chiral models such as the linear and nonlinear sigma model will be discussed as well as the essential ideas of chiral perturbation theory. Some applications to the physics of ultrarelativistic heavy ion collisions will be presented
Quantum entanglement of unitary operators on bi-partite systems
Wang, X.; Zanardi, P.
2002-01-01
We study the entanglement of unitary operators on $d_1\\times d_2$ quantum systems. This quantity is closely related to the entangling power of the associated quantum evolutions. The entanglement of a class of unitary operators is quantified by the concept of concurrence.
Quantum fidelity and relative entropy between unitary orbits
Fidelity and relative entropy are two significant quantities in quantum information theory. We study the quantum fidelity and relative entropy under unitary orbits. The maximal and minimal quantum fidelity and relative entropy between two unitary orbits are explicitly derived. The potential applications in quantum computation and information processing are discussed. (paper)
Two-dimensional gravity and its W3-extension: Strongly coupled unitary theories
For strongly coupled 2D-gravity, with central charge Cgrav=1+6(s+2), s=0, ±1, a chiral (2,2)-operator Φ satisfies a closed exchange algebra on the unit circle, with a consistent restriction to a unitary subspace of the Virasoro representation. In this paper, this result of Gervais and Neveu is first extended to a larger unitary space, with characters equal to those of a free boson compactified on a circle with radius √2(2-s). Second, Φ is shown to take a simple form when expressed in terms of the operators whose exchange algebra coincides with the universal R-matrix of the quantum group SL(2)q. Third, in the case of strongly coupled A2 Toda theories, i.e. 'W3-extended 2D-gravity', the generalization of the Φ-field is obtained for CT=2+24(s+2). Going from A1 (Liovilletriple bond2D-gravity) to A2 brings in interesting novel features, such as an intriguing U(1) gauge field configuration defined on the A2 weight lattice. (orig.)
Liu, Keh-Fei
2016-01-01
The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.
The Macromolecular Route to Chiral Amplification.
Green; Park; Sato; Teramoto; Lifson; Selinger; Selinger
1999-11-01
Cooperative phenomena, described by one-dimensional statistical physical methods, are observed between the enantiomeric characteristics of monomeric materials and the polymers they produce. The effect of minute energies associated with this amplified chirality, although currently not interpretable, can be easily measured. Nonlinear relationships between enantiomeric excess or enantiomeric content and polymer properties may offer the possibility of developing chiral catalysts and chiral chromatographic materials in which the burden of large enantiomeric excess or content may be considerably alleviated. New approaches to information and sensor technology may become possible. PMID:10556885
Unitary Operators, Entanglement, and Gram-Schmidt Orthogonalization
Hardy, Yorick; Steeb, Willi-Hans
We consider finite-dimensional Hilbert spaces { H} with dim ({ H}) =n with n ≥ 2 and unitary operators. In particular, we consider the case n = 2m, where m ≥ 2 in order to study entanglement of states in these Hilbert spaces. Two normalized states ψ and ϕ in these Hilbert spaces { H} are connected by a unitary transformation (n×n unitary matrices), i.e. ψ = Uϕ, where U is a unitary operator UU* = I. Given the normalized states ψ and ϕ, we provide an algorithm to find this unitary operator U for finite-dimensional Hilbert spaces. The construction is based on a modified Gram-Schmidt orthonormalization technique. A number of applications important in quantum computing are given. Symbolic C++ is used to give a computer algebra implementation in C++.
Unitary dynamics of spherical null gravitating shells
Hajicek, P
2001-01-01
The dynamics of a thin spherically symmetric shell of zero-rest-mass matter in its own gravitational field is studied. A form of action principle is used that enables the reformulation of the dynamics as motion on a fixed background manifold. A self-adjoint extension of the Hamiltonian is obtained via the group quantization method. Operators of position and of direction of motion are constructed. The shell is shown to avoid the singularity, to bounce and to reexpand to that asymptotic region from which it contracted; the dynamics is, therefore, truly unitary. If a wave packet is sufficiently narrow and/or energetic then an essential part of it can be concentrated under its Schwarzschild radius near the bounce point but no black hole forms. The quantum Schwarzschild horizon is a linear combination of a black and white hole apparent horizons rather than an event horizon.
New identities between unitary minimal Virasoro characters
Taormina, Anne
1994-10-01
Two sets of identities between unitary minimal Virasoro characters at levels m=3, 4, 5 are presented and proven. The first identity suggests a connection between the Ising and the tricritical Ising models since the m=3 Virasoro characters are obtained as bilinears of m=4 Virasoro characters. The second identity given the tricritical Ising model characters as bilinears in the Ising model characters and the six combinations of m=5 Virasoro characters which do not appear in the spectrum of the three state Potts model. The implication of these identities on the study of the branching rules of N=4 superconformal characters intoSwidehat{U(2)} × Swidehat{U(2)} characters is discussed.
New Identities between Unitary Minimal Virasoro Characters
Taormina, A
1994-01-01
Two sets of identities between unitary minimal Virasoro characters at levels $m=3,4,5$ are presented and proven. The first identity suggests a connection between the Ising and tricritical Ising models since the $m=3$ Virasoro characters are obtained as bilinears of $m=4$ Virasoro characters. The second identity gives the tricritical Ising model characters as bilinears in the Ising model characters and the six combinations of $m=5$ Virasoro characters which do not appear in the spectrum of the three state Potts model. The implication of these identities on the study of the branching rules of $N=4$ superconformal characters into $\\widehat{SU(2)} \\times \\widehat{SU(2)}$ characters is discussed.
Secular determinants of random unitary matrices
Haake, F; Schomerus, H; Haake, Fritz; Kus, Marek; Schomerus, Henning
1996-01-01
We consider the characteristic polynomials of random unitary matrices U drawn from various circular ensembles. In particular, the statistics of the coefficients of these polynomials are studied. The variances of these ``secular coefficients'' are given explicitly for arbitrary dimension and continued analytically to arbitrary values of the level repulsion exponent \\beta. The latter secular coefficients are related to the traces of powers of U by Newton's well-known formulae. While the traces tend to have Gaussian distributions and to be statistically independent among one another in the limit as the matrix dimension grows large, the secular coefficients exhibit strong mutual correlations due to Newton's mixing of traces to coefficients. These results might become relevant for current efforts at combining semiclassics and random-matrix theory in quantum treatments of classically chaotic dynamics.
Christian, J.E.
1977-07-01
This technology evaluation covers commercially available unitary heat pumps ranging from nominal capacities of 1/sup 1///sub 2/ to 45 tons. The nominal COP of the heat pump models, selected as representative, vary from 2.4 to 2.9. Seasonal COPs for heat pump installations and single-family dwellings are reported to vary from 2.5 to 1.1, depending on climate. For cooling performance, the nominal EER's vary from 6.5 to 8.7. Representative part-load performance curves along with cost estimating and reliability data are provided to aid: (1) the systems design engineer to select suitably sized heat pumps based on life-cycle cost analyses, and (2) the computer programmer to develop a simulation code for heat pumps operating in an Integrated Community Energy System.
Chiral Rotational Spectroscopy
Cameron, Robert P; Barnett, Stephen M
2015-01-01
We introduce chiral rotational spectroscopy: a new technique that enables the determination of the individual optical activity polarisability components $G_{XX}'$, $G_{YY}'$, $G_{ZZ}'$, $A_{X,YZ}$, $A_{Y,ZX}$ and $A_{Z,XY}$ of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample whilst yielding an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral by virtue of their isotopic constitution and molecules with multiple chiral centres. The principles that underpin chiral rotational spectroscopy can also be exploited in the search for molecular chirality in space, which, if found, may add weight to hypotheses that biological homochirality and indeed life itself are of cosmic origin.
On chiral and non chiral 1D supermultiplets
Toppan, Francesco, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (TEO/CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Fisica Teorica
2011-07-01
In this talk I discuss and clarify some issues concerning chiral and non chiral properties of the one-dimensional supermultiplets of the N-extended supersymmetry. Quaternionic chirality can be defined for N = 4, 5, 6, 7, 8. Octonionic chirality for N = 8 and beyond. Inequivalent chiralities only arise when considering several copies of N = 4 or N = 8 supermultiplets. (author)
Chiral symmetry and chiral-symmetry breaking
Peskin, M.E.
1982-12-01
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)
Chiral symmetry and lattice gauge theory
I review the problem of formulating chiral symmetry in lattice gauge theory. I discuss recent approaches involving an infinite tower of additional heavy states to absorb Fermion doublers. For hadronic physics this provides a natural scheme for taking quark masses to zero without requiring a precise tuning of parameters. A mirror Fermion variation provides a possible way of extending the picture to chirally coupled light Fermions
Adesso, Gerardo; Giampaolo, Salvatore M.; Illuminati, Fabrizio
2007-01-01
We present a geometric approach to the characterization of separability and entanglement in pure Gaussian states of an arbitrary number of modes. The analysis is performed adapting to continuous variables a formalism based on single subsystem unitary transformations that has been recently introduced to characterize separability and entanglement in pure states of qubits and qutrits [arXiv:0706.1561]. In analogy with the finite-dimensional case, we demonstrate that the $1 \\times M$ bipartite en...
Kalaydzhyan, Tigran
2014-01-01
We argue that the strongly coupled quark-gluon plasma formed at LHC and RHIC can be considered as a chiral superfluid. The "normal" component of the fluid is the thermalized matter in common sense, while the "superfluid" part consists of long wavelength (chiral) fermionic states moving independently. We use the bosonization procedure with a finite cut-off and obtain a dynamical axion-like field out of the chiral fermionic modes. Then we use relativistic hydrodynamics for macroscopic description of the effective theory obtained after the bosonization. Finally, solving the hydrodynamic equations in gradient expansion, we find that in the presence of external electromagnetic fields or rotation the motion of the "superfluid" component gives rise to the chiral magnetic, chiral vortical, chiral electric and dipole wave effects. Latter two effects are specific for a two-component fluid, which provides us with crucial experimental tests of the model.
Chiral solitons a review volume
1987-01-01
This review volume on topological and nontopological chiral solitons presents a global view on the current developments of this field in particle and nuclear physics. The book addresses problems in quantization, restoration of translational and rotational symmetry, and the field theoretical approach to solitons which are common problems in the field of solitons. Primarily aimed for graduate students and the novice in the field, the collected articless cover a broad spectrum of topics in formalism as well as phenomenology.
Quantum Monte Carlo calculations with chiral effective field theory interactions
The neutron-matter equation of state connects several physical systems over a wide density range, from cold atomic gases in the unitary limit at low densities, to neutron-rich nuclei at intermediate densities, up to neutron stars which reach supranuclear densities in their core. An accurate description of the neutron-matter equation of state is therefore crucial to describe these systems. To calculate the neutron-matter equation of state reliably, precise many-body methods in combination with a systematic theory for nuclear forces are needed. Chiral effective field theory (EFT) is such a theory. It provides a systematic framework for the description of low-energy hadronic interactions and enables calculations with controlled theoretical uncertainties. Chiral EFT makes use of a momentum-space expansion of nuclear forces based on the symmetries of Quantum Chromodynamics, which is the fundamental theory of strong interactions. In chiral EFT, the description of nuclear forces can be systematically improved by going to higher orders in the chiral expansion. On the other hand, continuum Quantum Monte Carlo (QMC) methods are among the most precise many-body methods available to study strongly interacting systems at finite densities. They treat the Schroedinger equation as a diffusion equation in imaginary time and project out the ground-state wave function of the system starting from a trial wave function by propagating the system in imaginary time. To perform this propagation, continuum QMC methods require as input local interactions. However, chiral EFT, which is naturally formulated in momentum space, contains several sources of nonlocality. In this Thesis, we show how to construct local chiral two-nucleon (NN) and three-nucleon (3N) interactions and discuss results of first QMC calculations for pure neutron systems. We have performed systematic auxiliary-field diffusion Monte Carlo (AFDMC) calculations for neutron matter using local chiral NN interactions. By
Quantum Monte Carlo calculations with chiral effective field theory interactions
Tews, Ingo
2015-10-12
The neutron-matter equation of state connects several physical systems over a wide density range, from cold atomic gases in the unitary limit at low densities, to neutron-rich nuclei at intermediate densities, up to neutron stars which reach supranuclear densities in their core. An accurate description of the neutron-matter equation of state is therefore crucial to describe these systems. To calculate the neutron-matter equation of state reliably, precise many-body methods in combination with a systematic theory for nuclear forces are needed. Chiral effective field theory (EFT) is such a theory. It provides a systematic framework for the description of low-energy hadronic interactions and enables calculations with controlled theoretical uncertainties. Chiral EFT makes use of a momentum-space expansion of nuclear forces based on the symmetries of Quantum Chromodynamics, which is the fundamental theory of strong interactions. In chiral EFT, the description of nuclear forces can be systematically improved by going to higher orders in the chiral expansion. On the other hand, continuum Quantum Monte Carlo (QMC) methods are among the most precise many-body methods available to study strongly interacting systems at finite densities. They treat the Schroedinger equation as a diffusion equation in imaginary time and project out the ground-state wave function of the system starting from a trial wave function by propagating the system in imaginary time. To perform this propagation, continuum QMC methods require as input local interactions. However, chiral EFT, which is naturally formulated in momentum space, contains several sources of nonlocality. In this Thesis, we show how to construct local chiral two-nucleon (NN) and three-nucleon (3N) interactions and discuss results of first QMC calculations for pure neutron systems. We have performed systematic auxiliary-field diffusion Monte Carlo (AFDMC) calculations for neutron matter using local chiral NN interactions. By
Mechanical separation of chiral dipoles by chiral light
Canaguier-Durand, Antoine; Genet, Cyriaque; Ebbesen, Thomas W
2013-01-01
Optical forces take on a specific form when involving chiral light fields interacting with chiral objects. We show that optical chirality density and flow can have mechanical effects through reactive and dissipative components of chiral forces exerted on chiral dipoles. Remarkably, these force components are directly related to standard observables: optical rotation and circular dichroism, respectively. As a consequence, resulting forces and torques are dependent on the enantiomeric form of the chiral dipole. This leads to promising strategies for the mechanical separation of chiral objects using chiral light forces.
Chiral chemistry of metal-camphorate frameworks.
Gu, Zhi-Gang; Zhan, Caihong; Zhang, Jian; Bu, Xianhui
2016-06-01
This critical review presents the various synthetic approaches and chiral chemistry of metal-camphorate frameworks (MCamFs), which are homochiral metal-organic frameworks (MOFs) constructed from a camphorate ligand. The interest in this unique subset of homochiral MOFs is derived from the many interesting chiral features for both materials and life sciences, such as asymmetrical synthesis or crystallization, homochiral structural design, chiral induction, absolute helical control and ligand handedness. Additionally, we discuss the potential applications of homochiral MCamFs. This review will be of interest to researchers attempting to design other homochiral MOFs and those engaged in the extension of MOFs for applications such as chiral recognition, enantiomer separation, asymmetric catalysis, nonlinear sensors and devices. PMID:27021070
Nuclear Chiral EFT in the Precision Era
Epelbaum, Evgeny
2015-01-01
Chiral effective field theory has established itself as the method of choice to study nuclear forces and low-energy nuclear dynamics. I review the status and prospects of this approach and discuss ongoing efforts to advance the precision frontier for ab initio description of few-nucleon systems. Special emphasis is put on the precise determination of the two-nucleon force at fifth order in the chiral expansion, role of the chiral symmetry, the convergence pattern of the chiral expansion and the quantification of the theoretical uncertainties. The discussed topics are essential for ongoing studies towards elucidating the structure of the three-nucleon force which will be briefly addressed as well.
Chirally motivated K{sup -} nuclear potentials
Cieply, A. [Nuclear Physics Institute, 25068 Rez (Czech Republic); Friedman, E. [Racah Institute of Physics, Hebrew University, 91904 Jerusalem (Israel); Gal, A., E-mail: avragal@vms.huji.ac.il [Racah Institute of Physics, Hebrew University, 91904 Jerusalem (Israel); Gazda, D.; Mares, J. [Nuclear Physics Institute, 25068 Rez (Czech Republic)
2011-08-26
In-medium subthreshold K-bar N scattering amplitudes calculated within a chirally motivated meson-baryon coupled-channel model are used self consistently to confront K{sup -} atom data across the periodic table. Substantially deeper K{sup -} nuclear potentials are obtained compared to the shallow potentials derived in some approaches from threshold K-bar N amplitudes, with ReV{sub K}{sup chiral}=-(85{+-}5) MeV at nuclear matter density. When K-bar NN contributions are incorporated phenomenologically, a very deep K{sup -} nuclear potential results, ReV{sub K}{sup chiral+phen.}=-(180{+-}5) MeV, in agreement with density dependent potentials obtained in purely phenomenological fits to the data. Self consistent dynamical calculations of K{sup -}-nuclear quasibound states generated by V{sub K}{sup chiral} are reported and discussed.
A unitary test of the Ratios Conjecture
Goes, John; Miller, Steven J; Montague, David; Ninsuwan, Kesinee; Peckner, Ryan; Pham, Thuy
2009-01-01
The Ratios Conjecture of Conrey, Farmer and Zirnbauer predicts the answers to numerous questions in number theory, ranging from n-level densities and correlations to mollifiers to moments and vanishing at the central point. The conjecture gives a recipe to generate these answers, which are believed to be correct up to square-root cancelation. These predictions have been verified, for suitably restricted test functions, for the 1-level density of orthogonal and symplectic families of L-functions. In this paper we verify the conjecture's predictions for the unitary family of all Dirichlet $L$-functions with prime conductor; we show square-root agreement between prediction and number theory if the support of the Fourier transform of the test function is in (-1,1), and for support up to (-2,2) we show agreement up to a power savings in the family's cardinality. The interesting feature in this family (which has not surfaced in previous investigations) is determining what is and what is not a diagonal term in the R...
Quantum Entanglement Growth Under Random Unitary Dynamics
Nahum, Adam; Vijay, Sagar; Haah, Jeongwan
2016-01-01
Characterizing how entanglement grows with time in a many-body system, for example after a quantum quench, is a key problem in non-equilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing either Hamiltonian evolution with time--dependent noise or evolution by a random quantum circuit. Our results reveal a universal structure behind noisy entanglement growth, and also provide simple new heuristics for the `entanglement tsunami' in Hamiltonian systems without noise. In 1D, we show that noise causes the entanglement entropy across a cut to grow according to the celebrated Kardar--Parisi--Zhang (KPZ) equation. The mean entanglement grows linearly in time, while fluctuations grow like $(\\text{time})^{1/3}$ and are spatially correlated over a distance $\\propto (\\text{time})^{2/3}$. We derive KPZ universal behaviour in three complementary ways, by mapping random entanglement growth to: (i) a stochastic model of a growing surface; (ii) a `minimal cut' picture, reminisce...
Nozzle dam having a unitary plug
Veronesi, Luciano; Wepfer, Robert M.
1992-01-01
Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening. Each plug includes a plurality of arms operable to engage the slots of the bracket for connecting each plug to the bracket, so that the nozzle is sealed as the plugs seal the openings and are connected to the bracket.
Unitary Transformations in Quantum Field Theory and Bound States
Shebeko, A V
2001-01-01
Finding the eigenstates of the total Hamiltonian H or its diagonalization is the important problem of quantum physics. However, in relativistic quantum field theory (RQFT) its complete and exact solution is possible for a few simple models only. Unitary transformations (UT's) considered in this survey do not diagonalize H, but convert H into a form which enables us to find approximately some H eigenstates. During the last years there have appeared many papers devoted to physical applications of such UT's. Our aim is to present a systematic and self-sufficient exposition of the UT method. The two general kinds of UT's are pointed out, distinct variations of each kind being possible. We consider in detail the problem of finding the simplest H eigenstates for interacting mesons and nucleons using the so-called ``clothing'' UT and Okubo's UT. These UT's allow us to suggest definite approaches to the problem of two-particle (deuteron-like) bound states in RQFT. The approaches are shown to yield the same two-nucleo...
Doped Chiral Polymer Metamaterials Project
National Aeronautics and Space Administration — Doped Chiral Polymer Metamaterials (DCPM) with tunable resonance frequencies have been developed by adding plasmonic inclusions into chiral polymers with variable...
Virial theorem and universality in a unitary fermi gas.
Thomas, J E; Kinast, J; Turlapov, A
2005-09-16
Unitary Fermi gases, where the scattering length is large compared to the interparticle spacing, can have universal properties, which are independent of the details of the interparticle interactions when the range of the scattering potential is negligible. We prepare an optically trapped, unitary Fermi gas of 6Li, tuned just above the center of a broad Feshbach resonance. In agreement with the universal hypothesis, we observe that this strongly interacting many-body system obeys the virial theorem for an ideal gas over a wide range of temperatures. Based on this result, we suggest a simple volume thermometry method for unitary gases. We also show that the observed breathing mode frequency, which is close to the unitary hydrodynamic value over a wide range of temperature, is consistent with a universal hydrodynamic gas with nearly isentropic dynamics. PMID:16197054
Mutually unbiased bases generated by a single unitary operator
Ranade, Kedar [Institut fuer Quantenphysik, Universitaet Ulm (Germany); Kern, Oliver; Seyfarth, Ulrich [Institut fuer Angewandte Physik, Technische Universitaet Darmstadt (Germany)
2010-07-01
In this talk, we discuss a method for constructing unitary operators which generate mutually unbiased bases on Hilbert spaces H=C{sup d} for d being a power-of-two dimension (i. e. d = 2{sup m}, m element of N). Such operators U have order d+1, and the columns of U,U{sup 2},.., U{sup d+1} = 1 define mutually unbiased bases. The construction is based on finding a maximal commuting unitary operator basis of the matrix algebra associated to the Hilbert space and a Clifford group unitary transformation which maps the equivalence classes of a partition of this operator basis onto another. We explicitly construct unitary operators which generate mutually unbiased bases in all dimensions d = 2{sup m} for m{<=}22.
Gaussian elimination in unitary groups with an application to cryptography
Mahalanobis, Ayan; Singh, Anupam
2014-01-01
Gaussian elimination is used in special linear groups to solve the word problem. In this paper, we extend Gaussian elimination to unitary groups. These algorithms have an application in building a public-key cryptosystem, we demonstrate that.
Partition function of a chiral boson on a 2-torus from the Floreanini–Jackiw Lagrangian
We revisit the problem of quantizing a chiral boson on a torus. The conventional approach is to extract the partition function of a chiral boson from the path integral of a non-chiral boson. Instead we compute it directly from the chiral boson Lagrangian of Floreanini and Jackiw modified by topological terms involving an auxiliary field. A careful analysis of the gauge-fixing condition for the extra gauge symmetry reproduces the correct results for the free chiral boson, and has the advantage of being applicable to a wider class of interacting chiral boson theories
Reducible chiral four-body interactions in nuclear matter
Kaiser, N.; Milkus, R. [Technische Universitaet Muenchen, Physik-Department T39, Garching (Germany)
2016-01-15
The method of unitary transformations generates five classes of leading-order reducible chiral four-nucleon interactions which involve pion exchanges and a spin-spin contact term. Their first-order contributions to the energy per particle of isospin-symmetric nuclear matter and pure neutron matter are evaluated in detail. For most of the closed four-loop diagrams the occurring integrals over four Fermi spheres can be reduced to easily manageable one- or two-parameter integrals. One finds substantial compensations among the different contributions arising from 2-ring and 1-ring diagrams. Altogether, the net attraction generated by the chiral four-nucleon interaction does not exceed values of -1.3 MeV for densities ρ < 2ρ{sub 0}. (orig.)
On the generalized unitary parasupersymmetry algebra of Beckers-Debergh
Chenaghlou, A.; H. Fakhri
2002-01-01
An appropriate generalization of the unitary parasupersymmetry algebra of Beckers-Debergh to arbitrary order is presented in this paper. A special representation for realizing of the even arbitrary order unitary parasupersymmetry algebra of Beckers-Debergh is analyzed by one dimensional shape invariance solvable models, 2D and 3D quantum solvable models obtained from the shape invariance theory as well. In particular in the special representation, it is shown that the isospectrum Hamiltonians...
The Theory of Unitary Development of Chengdu and Chongqing
HuangQing
2005-01-01
Chengdu and Chongqing are two megalopolises with the synthesized economic strength and the strongest urban competitiveness in the entire western region, which have very important positions in the development of western China. Through horizontal contrast of social economic developing level of the two cities, the two cities' economic foundation of unitary development is analyzed from complementary and integrative relationship. Then the policies and measures of economic unitary development of two cities is put forward.
Amendable Gaussian channels:restoring entanglement via a unitary filter
Pasquale, A.; Mari, A.; Porzio, A.; Giovannetti, V.
2013-01-01
We show that there exist Gaussian channels which are amendable. A channel is amendable if when applied twice is entanglement breaking while there exists a unitary filter such that, when interposed between the first and second action of the map, prevents the global transformation from being entanglement breaking [Phys. Rev. A 86, 052302 (2012)]. We find that, depending on the structure of the channel, the unitary filter can be a squeezing transformation or a phase shift operation. We also prop...
Universal microscopic correlation functions for products of truncated unitary matrices
Akemann, Gernot; Burda, Zdzislaw; Kieburg, Mario; Nagao, Taro
2013-01-01
We investigate the spectral properties of the product of $M$ complex non-Hermitian random matrices that are obtained by removing $L$ rows and columns of larger unitary random matrices uniformly distributed on the group ${\\rm U}(N+L)$. Such matrices are called truncated unitary matrices or random contractions. We first derive the joint probability distribution for the eigenvalues of the product matrix for fixed $N,\\ L$, and $M$, given by a standard determinantal point process in the complex pl...
Quantifying nonclassicality: global impact of local unitary evolutions
Giampaolo S.M.; Streltsov A.; Roga W.; Bruss D.; Illuminati F.
2012-01-01
We show that only those composite quantum systems possessing nonvanishing quantum correlations have the property that any nontrivial local unitary evolution changes their global state. We derive the exact relation between the global state change induced by local unitary evolutions and the amount of quantum correlations. We prove that the minimal change coincides with the geometric measure of discord (defined via the Hilbert- Schmidt norm), thus providing the latter with an operational interpr...
Virial Theorem and Universality in a Unitary Fermi Gas
Thomas, J E; Kinast, J.; Turlapov, A.
2005-01-01
Unitary Fermi gases, where the scattering length is large compared to the interparticle spacing, can have universal properties, which are independent of the details of the interparticle interactions when the range of the scattering potential is negligible. We prepare an optically-trapped, unitary Fermi gas of $^6$Li, tuned just above the center of a broad Feshbach resonance. In agreement with the universal hypothesis, we observe that this strongly-interacting many-body system obeys the virial...
Time reversal and exchange symmetries of unitary gate capacities
Harrow, Aram W.; Shor, Peter W.
2005-01-01
Unitary gates are an interesting resource for quantum communication in part because they are always invertible and are intrinsically bidirectional. This paper explores these two symmetries: time-reversal and exchange of Alice and Bob. We will present examples of unitary gates that exhibit dramatic separations between forward and backward capacities (even when the back communication is assisted by free entanglement) and between entanglement-assisted and unassisted capacities, among many others...
Unitary relations in time-dependent harmonic oscillators
Song, Dae-Yup
1998-01-01
For a harmonic oscillator with time-dependent (positive) mass and frequency, an unitary operator is shown to transform the quantum states of the system to those of a harmonic oscillator system of unit mass and time-dependent frequency, as well as operators. For a driven harmonic oscillator, it is also shown that, there are unitary transformations which give the driven system from the system of same mass and frequency without driving force. The transformation for a driven oscillator depends on...
We present a geometric approach to the characterization of separability and entanglement in pure Gaussian states of an arbitrary number of modes. The analysis is performed adapting to continuous variables a formalism based on single subsystem unitary transformations that has been recently introduced to characterize separability and entanglement in pure states of qubits and qutrits [S. M. Giampaolo and F. Illuminati, Phys. Rev. A 76, 042301 (2007)]. In analogy with the finite-dimensional case, we demonstrate that the 1xM bipartite entanglement of a multimode pure Gaussian state can be quantified by the minimum squared Euclidean distance between the state itself and the set of states obtained by transforming it via suitable local symplectic (unitary) operations. This minimum distance, corresponding to a, uniquely determined, extremal local operation, defines an entanglement monotone equivalent to the entropy of entanglement, and amenable to direct experimental measurement with linear optical schemes
K operators and unitary approximations for the three-body problem
The method of channel coupling arrays is used as a means to introduce unitary approximations for the three-body problem. First, the transition operators defined by the channel coupling array equations are shown to obey the correct (on-shell) discontinuity equations. Next, K (reaction) operators are defined by using principal value Green's functions in the channel coupling array equations. These operators are then shown to be related to the transition operators by a damping equation which leads to the correct discontinuity relation. This development provides the basis for introducing unitary approximations, since any set of K operators having zero discontinuity will yield, through the damping equation, a set of transition operators having the proper singularity structure. The use of the channel coupling array method achieves this result without the need for introducing an intermediate hierarchy of operators, as in other approaches
Adesso, Gerardo; Giampaolo, Salvatore M.; Illuminati, Fabrizio
2007-10-01
We present a geometric approach to the characterization of separability and entanglement in pure Gaussian states of an arbitrary number of modes. The analysis is performed adapting to continuous variables a formalism based on single subsystem unitary transformations that has been recently introduced to characterize separability and entanglement in pure states of qubits and qutrits [S. M. Giampaolo and F. Illuminati, Phys. Rev. A 76, 042301 (2007)]. In analogy with the finite-dimensional case, we demonstrate that the 1×M bipartite entanglement of a multimode pure Gaussian state can be quantified by the minimum squared Euclidean distance between the state itself and the set of states obtained by transforming it via suitable local symplectic (unitary) operations. This minimum distance, corresponding to a , uniquely determined, extremal local operation, defines an entanglement monotone equivalent to the entropy of entanglement, and amenable to direct experimental measurement with linear optical schemes.
Detecting chirality in molecules by linearly polarized laser fields
Yachmenev, Andrey
2016-01-01
A new scheme for enantiomer differentiation of chiral molecules using a pair of linearly polarized intense ultrashort laser pulses with skewed mutual polarization is presented. The technique relies on the fact that the off-diagonal anisotropic contributions to the electric polarizability tensor for two enantiomers have different signs. Exploiting this property, we are able to excite a coherent unidirectional rotation of two enantiomers with a {\\pi} phase difference in the molecular electric dipole moment. The approach is robust and suitable for relatively high temperatures of molecular samples, making it applicable for selective chiral analysis of mixtures, and to chiral molecules with low barriers between enantiomers. As an illustration, we present nanosecond laser-driven dynamics of a tetratomic non-rigid chiral molecule with short-lived chirality. The ultrafast time scale of the proposed technique is well suited to study parity violation in molecular systems in short-lived chiral states.
Detecting Chirality in Molecules by Linearly Polarized Laser Fields
Yachmenev, Andrey; Yurchenko, Sergei N.
2016-07-01
A new scheme for enantiomer differentiation of chiral molecules using a pair of linearly polarized intense ultrashort laser pulses with skewed mutual polarization is presented. The technique relies on the fact that the off-diagonal anisotropic contributions to the electric polarizability tensor for two enantiomers have different signs. Exploiting this property, we are able to excite a coherent unidirectional rotation of two enantiomers with a π phase difference in the molecular electric dipole moment. The approach is robust and suitable for relatively high temperatures of molecular samples, making it applicable for selective chiral analysis of mixtures, and to chiral molecules with low barriers between enantiomers. As an illustration, we present nanosecond laser-driven dynamics of a tetratomic nonrigid chiral molecule with short-lived chirality. The ultrafast time scale of the proposed technique is well suited to study parity violation in molecular systems in short-lived chiral states.
Chiral geometry in multiple chiral doublet bands
Zhang, Hao; Chen, Qibo
2016-02-01
The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with . The energy spectra, electromagnetic transition probabilities B(M1) and B(E2), angular momenta, and K-distributions are studied. It is demonstrated that the chirality still remains not only in the yrast and yrare bands, but also in the two higher excited bands when γ deviates from 30°. The chiral geometry relies significantly on γ, and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands. Supported by Plan Project of Beijing College Students’ Scientific Research and Entrepreneurial Action, Major State 973 Program of China (2013CB834400), National Natural Science Foundation of China (11175002, 11335002, 11375015, 11461141002), National Fund for Fostering Talents of Basic Science (NFFTBS) (J1103206), Research Fund for Doctoral Program of Higher Education (20110001110087) and China Postdoctoral Science Foundation (2015M580007)
Polarized pK{sup -} scattering in Unitary Baryon Chiral Perturbation Theory
Bouzas, Antonio O. [CINVESTAV-IPN, Departamento de Fisica Aplicada, Carretera Antigua a Progreso Km. 6, Apdo. Postal 73 ' ' Cordemex' ' , Merida, Yucatan (Mexico)
2010-03-15
We study pK{sup -} scattering in the energy range from threshold through the {lambda} (1520) peak in UBChPT, taking into account O(q) vertices from meson-baryon contact interactions and s- and u-channel ground-state baryon exchange, s- and u-channel decuplet- and nonet-baryon exchange and t -channel vector-meson exchange, as well as O(q {sup 2}) flavor-breaking vertices. Detailed fits to data are presented, including a substantial body of differential cross-section data with meson momentum q{sub lab} >300 MeV not considered in previous treatments. (orig.)
In this paper, Lorentzian wormholes with a phantom field and chiral matter fields have been obtained. In addition, it is shown that for different values of the gravitational coupling of the chiral fields, the wormhole geometry changes. Finally, the stability of the corresponding wormholes is studied and it is shown that are unstable (eg. Ellis's wormhole instability)