Quantum Physics

Non-Hermitian exciton dynamics in a photosynthetic unit system

A. Thilagam
The non-Hermitian quantum dynamics of excitonic energy transfer in photosynthetic systems is investigated using a dissipative two-level dimer model. The approach is based on Green's function formalism which permits consideration of decoherence and intersite transfer processes on comparable terms. Th ... [J. Chem. Phys. 136, 065104 (2012)] published Mon Feb 13, 2012.

Delay time in quaternionic quantum mechanics

Stefano De Leo and Gisele Ducati
In looking for quaternionic violations of quantum mechanics, we discuss the delay time for pure quaternionic potentials. Our study shows the energy region which amplifies the difference between quaternionic and complex quantum mechanics. ... [J. Math. Phys. 53, 022102 (2012)] published Mon Feb 13, 2012.

Quantum Memory Assisted Probing of Dynamical Spin Correlations

O. Romero-Isart, M. Rizzi, C. A. Muschik, E. S. Polzik, M. Lewenstein et al.
We propose a method to probe time-dependent correlations of nontrivial observables in many-body ultracold lattice gases. The scheme uses a quantum nondemolition matter-light interface, first to map the observable of interest on the many-body system into the light and then to store coherently such in ... [Phys. Rev. Lett. 108, 065302 ] published .

Quantum statistics and thermodynamics in the harmonic approximation

J. R. Armstrong, N. T. Zinner, D. V. Fedorov, and A. S. Jensen
We describe a method to compute thermodynamic quantities in the harmonic approximation for identical bosons and fermions in an external confining field. We use the canonical partition function where only energies and their degeneracies enter. The number of states of given energy and symmetry is foun ... [Phys. Rev. E 85, 021117 ] published .

Fermionic Casimir densities in a conical space with a circular boundary and magnetic flux

E. R. Bezerra de Mello, F. Moraes, and A. A. Saharian
The vacuum expectation value (VEV) of the energy-momentum tensor for a massive fermionic field is investigated in a (2+1)-dimensional conical spacetime in the presence of a circular boundary and an infinitely thin magnetic flux located at the cone apex. The MIT bag boundary condition is assumed on t ... [Phys. Rev. D 85, 045016 ] published .

Relativistic corrections to the semi-inclusive decay of psi and Upsilon

Hai-Ting Chen, Yu-Qi Chen, and Wen-Long Sang
In the framework of the nonrelativistic quantum chromodynamics factorization formalism, we study the processes of psi(nS) and Upsilon(nS) decay into a lepton pair or a charm pair associated with two jets up to the next-to-leading order in velocity expansion. We present the analytic expressions for t ... [Phys. Rev. D 85, 034017 ] published .

Predictions for p + Pb at 4.4A TeV to test initial-state nuclear shadowing at energies available at the CERN Large Hadron Collider

G. G. Barnafoldi, J. Barrette, M. Gyulassy, P. Levai, and V. Topor Pop
Collinear factorized perturbative QCD model predictions are compared for p+Pb at 4.4A TeV to test nuclear shadowing of parton distribution at the CERN Large Hadron Collider (LHC). The nuclear modification factor (NMF), R(y=0,p<20 GeV/c)=dn/[N(b)dn], is computed with an electron-nucleus (e+A) global ... [Phys. Rev. C 85, 024903 ] published .

Energy relaxation at quantum Hall edge

Ivan P. Levkivskyi and Eugene V. Sukhorukov
In this work, we address the recent experiments [C. Altimiras et al., Nat. Phys. 6, 34 (2010); H. le Sueur et al., Phys. Rev. Lett. 105, 056803 (2010);C. Altimiras et al., Phys. Rev. Lett. 105, 226804 (2010)], where an electron distribution function at the quantum Hall (QH) edge at filling factor nu ... [Phys. Rev. B 85, 075309 ] published .

Erratum: Measure of nonclassical correlation in coherence-vector representation [Phys. Rev. A 84, 062105 (2011)]

Tao Zhou, Jingxin Cui, and Gui Lu Long
Abstract not available. [Phys. Rev. A 85, 029904 ] published .

Non-Markovian effects on the nonlocality of a qubit-oscillator system

Jie Li, Gerard McKeown, Fernando L. Semiao, and Mauro Paternostro
Non-Markovian evolutions are responsible for a wide variety of physically interesting effects. Here, we study nonlocality of the nonclassical state of a system consisting of a qubit and an oscillator exposed to the effects of non-Markovian evolutions. We find that the different facets of non-Markovi ... [Phys. Rev. A 85, 022116 ] published .

Experimental tomography of NOON states with large photon numbers

Y. Israel, I. Afek, S. Rosen, O. Ambar, and Y. Silberberg
We have performed experimental quantum state tomography of NOON states with up to four photons. The measured states are generated by mixing photons from a classical coherent state with down-converted photon pairs. We show that the fidelity between the produced states and the ideal NOON states is hig ... [Phys. Rev. A 85, 022115 ] published .

Phononic crystal diffraction gratings

Rayisa P. Moiseyenko, Sarah Herbison, Nico F. Declercq, and Vincent Laude
When a phononic crystal is interrogated by an external source of acoustic waves, there is necessarily a phenomenon of diffraction occurring on the external enclosing surfaces. Indeed, these external surfaces are periodic and the resulting acoustic diffraction grating has a periodicity that depends o ... [J. Appl. Phys. 111, 034907 (2012)] published Fri Feb 10, 2012.

The coincidence limit of the graviton propagator in de Donder gauge on de Sitter background

E. O. Kahya, S. P. Miao, and R. P. Woodard
We explicitly work out the de Sitter breaking contributions to the recent solution for the de Donder gauge graviton propagator on de Sitter. We also provide explicit power series expansions for the two structure functions, which are suitable for implementing dimensional regularization. And we evalua ... [J. Math. Phys. 53, 022304 (2012)] published Fri Feb 10, 2012.

Metal-to-Insulator Transition and Electron-Hole Puddle Formation in Disordered Graphene Nanoribbons

Gerald Schubert and Holger Fehske
The experimentally observed metal-to-insulator transition in hydrogenated graphene is numerically confirmed for actual sized graphene samples and realistic impurity concentrations. The eigenstates of our tight-binding model with substitutional disorder corroborate the formation of electron-hole pudd ... [Phys. Rev. Lett. 108, 066402 ] published .

Erratum: Bell's theorem with and without inequalities for the three-qubit Greenberger-Horne-Zeilinger and W states [Phys. Rev. A 65, 032108 (2002)]

Adan Cabello
Abstract not available. [Phys. Rev. A 85, 029903 ] published .

Quantum theory analysis of triple photons generated by a chi process

A. Dot, A. Borne, B. Boulanger, K. Bencheikh, and J. A. Levenson
We present a quantum theoretical analysis of triple photons generated by a phase-matched third-order nonlinear process in a KTP crystal in a weak-interaction regime. We show that the quantum properties of the triple photons can be brought to light through optical second- and third-order sum frequenc ... [Phys. Rev. A 85, 023809 ] published .

Manifestation of quantum disordered wave functions with weak localization from conical second harmonic generation in ferroelectric crystal

H. H. Yu, H. J. Zhang, Z. P. Wang, H. H. Xu, Y. C. Wang et al.
The spatial structure of two-dimensional quantum disordered wave functions with weak localization (WL) is experimentally observed using a calcium barium niobate CaBaNbO (CBN-28) ferroelectric crystal illuminated by a pulsed laser beam. Non-collinear phase-matching in CBN-28 produces conical second h ... [Appl. Phys. Lett. 100, 061119 (2012)] published Thu Feb 9, 2012.

Realizing the Multiparticle Hanbury BrownTwiss Interferometer Using Nitrogen-Vacancy Centers in Diamond Crystals

Li Dai and L. C. Kwek
We demonstrate that the multiparticle Hanbury BrownTwiss interferometer can be realized in a network of nitrogen-vacancy centers: for an N-particle system, the interference effect is manifested only in the Nth-order intensity correlation function. The interference effect can be enhanced through a po ... [Phys. Rev. Lett. 108, 066803 ] published .

Complete Set of Operational Measures for the Characterization of Three-Qubit Entanglement

J. I. de Vicente, T. Carle, C. Streitberger, and B. Kraus
We characterize the entanglement contained in a pure three-qubit state via operational entanglement measures. To this end, we derive a new decomposition for arbitrary three-qubit states which is characterized by five parameters (up to local unitary operations). We show that these parameters are uniq ... [Phys. Rev. Lett. 108, 060501 ] published .

Thermodynamics of ideal gas in doubly special relativity

Nitin Chandra and Sandeep Chatterjee
We study thermodynamics of an ideal gas in doubly special relativity. A new type of special functions (which we call incomplete modified Bessel functions) emerge. We obtain a series solution for the partition function and derive thermodynamic quantities. We observe that doubly special relativity the ... [Phys. Rev. D 85, 045012 ] published .

Decoherence-induced conductivity in the discrete one-dimensional Anderson model: A novel approach to even-order generalized Lyapunov exponents

Matias Zilly, Orsolya Ujsaghy, Marko Woelki, and Dietrich E. Wolf
A recently proposed statistical model for the effects of decoherence on electron transport manifests a decoherence-driven transition from quantum-coherent localized to Ohmic behavior when applied to the one-dimensional Anderson model. Here we derive the resistivity in the Ohmic case and show that th ... [Phys. Rev. B 85, 075110 ] published .

Influence of Coulomb interaction on the Aharonov-Bohm effect in an electronic Fabry-Perot interferometer

Stephane Ngo Dinh and Dmitry A. Bagrets
We study the role of Coulomb interaction in an electronic Fabry-Perot interferometer (FPI) realized with chiral edge states in the integer quantum Hall regime in the limit of weak backscattering. Assuming that a compressible Coulomb island in a bulk region of the FPI is formed, we develop a capacita ... [Phys. Rev. B 85, 073403 ] published .

Overcoming decoherence in the collapse and revival of spin Schrodinger-cat states

M. J. Everitt, W. J. Munro, and T. P. Spiller
In addition to being a very interesting quantum phenomenon, Schrodinger-cat-state swapping has the potential for application in the preparation of quantum states that could be used in metrology and other quantum processing. We study in detail the effects of field decoherence on a Schrodinger-cat-sta ... [Phys. Rev. A 85, 022113 ] published .

Correlations in optically controlled quantum emitters

Cristian E. Susa and John H. Reina
We address the problem of optically controlling and quantifying the dissipative dynamics of quantum and classical correlations in a setup of individual quantum emitters under external laser excitation. We show that both types of correlations, the former measured by the quantum discord, are present i ... [Phys. Rev. A 85, 022111 ] published .

Field theoretic approach to roughness corrections

Hua Yao Wu and Martin Schaden
We develop a systematic field theoretic description of roughness corrections to the Casimir free energy of a massless scalar field in the presence of parallel plates with mean separation a. Roughness is modeled by specifying a generating functional for correlation functions of the height profile. Th ... [Phys. Rev. D 85, 045008 ] published .

Contrasting features of anisotropic loop quantum cosmologies: The role of spatial curvature

Brajesh Gupt and Parampreet Singh
A characteristic feature of loop quantization of the isotropic and Bianchi-I spacetimes is the existence of universal bounds on the energy density and the expansion and shear scalars, independent of the matter content. We investigate the properties of these physical quantities in Bianchi-II and Bian ... [Phys. Rev. D 85, 044011 ] published .

Pion wave functions from holographic QCD and the role of infrared renormalons in photon-photon collisions

A. I. Ahmadov, C. Aydin, and F. Keskin
In this article, we calculate the contribution of the higher-twist Feynman diagrams to the large-p inclusive single pion production cross section in photon-photon collisions in case of the running coupling and frozen coupling approaches within holographic QCD. We compare the resummed higher-twist cr ... [Phys. Rev. D 85, 034009 ] published .

Flavor SU(4) breaking between effective couplings

Bruno El-Bennich, Gastao Krein, Lei Chang, Craig D. Roberts, and David J. Wilson
Using a framework in which all elements are constrained by Dyson-Schwinger equation studies in QCD, and therefore incorporate a consistent, direct and simultaneous description of light- and heavy-quarks and the states they constitute, we analyze the accuracy of SU(4)-flavor symmetry relations betwee ... [Phys. Rev. D 85, 031502 ] published .

Ground-state degeneracy in the Levin-Wen model for topological phases

Yuting Hu, Spencer D. Stirling, and Yong-Shi Wu
We study the properties of topological phases by calculating the ground-state degeneracy (GSD) of the two-dimensional Levin-Wen (LW) model. Here it is explicitly shown that the GSD depends only on the spatial topology of the system. Then we show that the ground state on a sphere is always nondegener ... [Phys. Rev. B 85, 075107 ] published .

Shear modulus of an elastic solid under external pressure as a function of temperature: The case of helium

Felipe Barra, Fernando Lund, Nicolas Mujica, and Sergio Rica
The energy of a dislocation loop in a continuum elastic solid under pressure is considered within the framework of classical mechanics. For a circular loop, this is a function with a maximum at pressures that are well within reach of experimental conditions for solid helium, suggesting, in this case ... [Phys. Rev. B 85, 064103 ] published .

Back-reaction effects of quantum vacuum in cavity quantum electrodynamics

I. Carusotto, S. De Liberato, D. Gerace, and C. Ciuti
We theoretically study an optical system in which the back-reaction of quantum vacuum manifests itself as a sizable suppression of the absorption by a three-level emitter embedded in an optical cavity. A theoretical model including the anti-rotating-wave terms of the light-matter interaction Hamilto ... [Phys. Rev. A 85, 023805 ] published .

Number-phase Wigner representation for scalable stochastic simulations of controlled quantum systems

M. R. Hush, A. R. R. Carvalho, and J. J. Hope
Simulation of conditional master equations is important to describe systems under continuous measurement and for the design of control strategies in quantum systems. For large bosonic systems, such as Bose-Einstein condensates and atom lasers, full quantum-field simulations must rely on scalable sto ... [Phys. Rev. A 85, 023607 ] published .

Interacting classical and quantum particles

Alvin J. K. Chua, Michael J. W. Hall, and C. M. Savage
We apply Hall and Reginatto's theory of interacting classical and quantum ensembles to harmonically coupled particles, with a view to understanding its experimental implications. This hybrid theory has no free parameters and makes distinctive predictions that should allow it to be experimentally dis ... [Phys. Rev. A 85, 022110 ] published .

NMR implementation of a quantum delayed-choice experiment

Soumya Singha Roy, Abhishek Shukla, and T. S. Mahesh
We report an experimental demonstration of a quantum delayed-choice experiment via nuclear magnetic resonance techniques. Two spin-1/2 nuclei from each molecule of a liquid ensemble are used as target and ancilla qubits. The circuit corresponding to the recently proposed quantum delayed-choice setup ... [Phys. Rev. A 85, 022109 ] published .

Local-channel-induced rise of quantum correlations in continuous-variable systems

Francesco Ciccarello and Vittorio Giovannetti
It was recently discovered that the quantum correlations of a pair of disentangled qubits, as measured by the quantum discord, can increase solely because of their interaction with a local dissipative bath. Here, we show that a similar phenomenon can occur in continuous-variable bipartite systems. W ... [Phys. Rev. A 85, 022108 ] published .

Triviality problem and high-temperature expansions of higher susceptibilities for the Ising and scalar-field models in four-, five-, and six-dimensional lattices

P. Butera and M. Pernici
High-temperature expansions are presently the only viable approach to the numerical calculation of the higher susceptibilities for the spin and the scalar-field models on high-dimensional lattices. The critical amplitudes of these quantities enter into a sequence of universal amplitude ratios that d ... [Phys. Rev. E 85, 021105 ] published .

Multiverse interpretation of quantum mechanics

Raphael Bousso and Leonard Susskind
We argue that the many worlds of quantum mechanics and the many worlds of the multiverse are the same thing, and that the multiverse is necessary to give exact operational meaning to probabilistic predictions from quantum mechanics. Decoherencethe modern version of wave-function collapseis subjectiv ... [Phys. Rev. D 85, 045007 ] published .

Resonant modulational instability and self-induced transmission effects in semiconductors: Maxwell-Bloch formalism

Oleksii A. Smyrnov and Fabio Biancalana
The nonlinear optical properties of semiconductors near an excitonic resonance are investigated theoretically by using the macroscopic J model [Ostreich and Knorr, Phys. Rev. B 48, 17811 (1993); and ibid. 50, 5717 (1994)] based on the microscopic semiconductor Bloch equations. These nonlinear prop ... [Phys. Rev. B 85, 075201 ] published .

Observers can always generate nonlocal correlations without aligning measurements by covering all their bases

Joel J. Wallman and Stephen D. Bartlett
Quantum theory allows for correlations between the outcomes of distant measurements that are inconsistent with any locally causal model, as demonstrated by the violation of a Bell inequality. Typical demonstrations of these correlations require careful alignment between the measurements, which requi ... [Phys. Rev. A 85, 024101 ] published .

Low-rank positive-partial-transpose states and their relation to product vectors

Leif Ove Hansen, Andreas Hauge, Jan Myrheim, and Per Oyvind Sollid
Deciding whether a mixed quantum state is separable or entangled is a difficult problem in general. Separable states are positive under partial transposition [they are positive-partial-transpose (PPT) states], but this simple test does not exclude all entangled states. In order to understand the ent ... [Phys. Rev. A 85, 022309 ] published .

Relation between wave-particle duality and quantum uncertainty

Hong-Yu Liu, Jie-Hui Huang, Jiang-Rui Gao, M. Suhail Zubairy, and Shi-Yao Zhu
We present a study of the relation between wave-particle duality and quantum uncertainty in a two-path interferometer and derive equalities and inequalities involving the visibility (representing wave-like behavior), the predictability (representing particle-like behavior), and their variances. We e ... [Phys. Rev. A 85, 022106 ] published .

Quantum state transmission in a cavity array via two-photon exchange. (arXiv:1202.2147v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Optimal multipartite entanglement concentration of electron-spin states based on charge detection and projection measurements. (arXiv:1202.2163v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Convex Geometry: a travel to the limits of our knowledge. (arXiv:1202.2164v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Effect of photoions on the line shapes of the F\"orster resonance and microwave transitions in cold rubidium Rydberg atoms. (arXiv:1202.2182v1 [physics.atom-ph])

ePrint arXiv http://arXiv.org/

General polygamy inequality of multi-party quantum entanglement. (arXiv:1202.2184v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Efficient single-photon-assisted entanglement concentration for partially entangled photon pairs. (arXiv:1202.2190v1 [quant-ph])

ePrint arXiv http://arXiv.org/

A Sequence of Quantum Gates. (arXiv:1202.2259v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Quantum Cournot equilibrium for the Hotelling-Smithies model of product choice. (arXiv:1202.2283v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Super-resolving multi-photon interferences with independent light sources. (arXiv:1202.2294v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Analytical treatment of bosonic d-wave scattering in isotropic harmonic waveguides. (arXiv:1202.2298v1 [physics.atom-ph])

ePrint arXiv http://arXiv.org/

Continuous quantum measurement and phase locking of a single trapped ion. (arXiv:1202.2307v1 [quant-ph])

ePrint arXiv http://arXiv.org/

Influence of the interplay between de Gennes boundary conditions and cubicity of Ginzburg-Landau equation on the properties of superconducting films. (arXiv:1202.2322v1 [cond-mat.mes-hall])

ePrint arXiv http://arXiv.org/