arXiv subjects

Y. Ben-Aryeh

Publications and source records attributed to Y. Ben-Aryeh.

At least 37 records · Page 2Linked to original sources

arXiv2015

Explicit constructions of all separable two-qubits density matrices and related problems for three-qubits systems

Explicitly separable density matrices are constructed for all separable two-qubits states based on Hilbert-Schmidt (HS) decompositions. For density matrices which include only two-qubits correlations the number of HS parameters is reduced to 3 by using local rotations, and for two-qubits states which include single qubit measurements, the number of parameters is reduced to 4 by local Lorentz transformations. For both cases we related the absolute values of the HS parameters to probabilities, and the outer products of various Pauli matrices were transformed to pure states density matrices products. Simple necessary and sufficient conditions for separability are derived. We discuss related problems for three qubits. For n-qubits correlation systems the sufficient condition for separability may be improved by local transformations, related to high order singular value decompositions.

quant-ph↗

arXiv2015

Strong and weak separability conditions for two-qubits density matrices

Explicit separable density matrices, for mixed two qubits states, are derived by the use of Hilbert Schmidt decompositions and Peres Horodecki criterion. A strongly separable two qubits mixed state is defined by multiplications of two density matrices given with pure states while weakly separable two qubits state is defined by multiplications of two density matrices which includes non-pure states. We find the sufficient and necessary condition for separability of two-qubits density matrices and show that under this condition the two-qubit density matrices are strongly separable.

quant-ph↗

arXiv2015

Bose Einstein condensation of excitons in planar systems, and superconductive phase transition temperature

A theoretical model is developed for treating super conductive Bose-Einstein condensation (BEC) effects for excitons in planar systems, under the condition that many excitons are included in a surface area, with the dimensions of the exciton center of mass de Broglie (dB) wave length, and under the condition that attractive forces are introduced between different excitons. The total internal energy of the excitonic system is found to be composed of the separate excitons positive energies, and negative energy due to scattering between different excitons. We assume that for high density of excitons, and corresponding attractive interactions between excitons, excitons in internal mode k are annihilated and in the same time excitons in internal mode k ' are created, where these scattering effects are integrated for all k and k ' values. It is assumed that the internal momenta of the excitonic system, remains in a quasi-stationary state, with approximately Bose distribution. Self-consistent equation for BEC of electrons-holes pairs and corresponding phase transition temperature are developed as function of electromagnetic interactions, experimental conditions and parameters. Possible applications by the use of the present theory are described

cond-mat.mes-hall↗

arXiv2014

The use of Braid operators for implementing entangled large n-QUBITS Bell states (n>2)

Braid theories are applied to quantum computation processes, where to each crossing in the Braid diagram a unitary Yang-Baxter operator R is associated, representing either a Braiding matrix or a universal quantum gate. By operating with Braid operators on the computational basis of n-QUBITS states, orthonormal entangled states are obtained, referred here as general Bell states. The 3-QUBITS Bell states are explicitly developed and the present methods are generalized to any n-QUBITS system. The quantum properties of the general Bell states are analyzed and these properties are related to concurrence

quant-ph↗

arXiv2013

Electrons and holes in planar systems and condensation by scattering of electrons-holes pairs in high-TC materials

Quantum field-theory is developed for treating electrons and holes in planar systems. Non-unitary representations of Dirac equation in the plane are developed. These equations can be used for treating holes-electron pairing in high TC materials where in a non-relativistic approximation we have a relatively small energy band gap. It is shown that while holes or electrons satisfy separately Pauli-exclusion principle, with anti-commutation relations, the holes-electron pairs follow boson commutation relations. The distribution for electrons-holes pairs in planar systems is calculated for the case in which scattering effects between different pairs can be neglected. It is shown that for high surface density in which many pairs are included in an area with wave length dimension, Bose-Einstein condensation can occur. The ground state of the Bose condensation is calculated and the calculations are compared with those of the BCS theory. The physical implications to high TC currents in planar systems are discussed. The present model is related to the chemistry of high-TC materials. PACS: 03.65.

cond-mat.supr-con↗

arXiv2013

A Variation of Dirac Equation, Based on SO(2,1) Group, with Applications to Low Dimensional Systems

A variation of Dirac equation based on SO(2,1) group is suggested for treating low dimensional systems in the three dimensional x,y,t space. Non-unitary representations are developed in an analogous way to those used in the ordinary Dirac equations and quantum field theory is developed for the present SO(2,1) relativistic equation. The theory is applied for low dimensional systems including especially holes-electrons pairs, or other two-particle states, in the low dimensional space.

math-ph↗

arXiv2012

Is Hardy's paradox a paradox?

In the present Note it is shown that Hardy thought experiment does not lead to any paradox and its explanation can be made by using quantum mechanical methods, without the need of weak measurements theories. The confusion arising about this thought experiment follows from ignoring the use of a projective measurement of the kind of knowledge. A certain comment about the realization of Hardy thought experiment with photons is made.

quant-ph↗

arXiv2012

Superresolution observed from evanescent waves transmitted through nano-corrugated metallic films

Plane EM waves transmitted through nano-corrugated metallic thin films produce evanescent waves which include the information on the nano-structures. The production of the evanescent waves at the metallic surface are analyzed. A microsphere located above the metallic surface collects the evanescent waves which are converted into propagating waves. The equations for the refraction at the boundary of the microsphere and the use of Snell's law for evanescent waves are developed. The magnification of the nano-structure images is explained by a geometric optics description, but the high resolution is related to the evanescent waves properties.

physics.optics↗

arXiv2012

Phase estimation by photon counting measurements in the output of a linear Mach Zehnder (MZI) interferometer

Photon counting measurements are analyzed for obtaining a classical phase parameter in linear Mach Zehnder interferometer (MZI), by the use of phase estimation theories. The detailed analysis is made for four cases: a) Coherent states inserted into the interferometer. b) Fock number state inserted in one input port of the interferometer and the vacuum into the other input port. c) Coherent state inserted into one input port of the interferometer and squeezed-vacuum state in the other input port. d) Exchanging the first beam-splitter (BS1) of a MZI by a non-linear system which inserts a NOON state into the interferometer and by using photon counting for parity measurements. The properties of photon counting for obtaining minimal phase uncertainties for the above special cases and for the general case are discussed.

quant-ph↗

arXiv2012

Collapse of the quantum wavefunction and Welcher-Weg (WW) experiments

The 'collapse' of the wave function in a general measuring process is analyzed by a pure quantum mechanical (QM) approach. The problem of the delayed choice and Welcher-Weg (WW) experiments is analyzed for Mach-Zehnder (MZ) interferometer. The WW effect is related to complementarity principle and orthogonality of wavefunctions although it produces small momentum changes between the electromagnetic (EM) field and the beam-splitters (BS's). For QM states for which we have a superposition of states and interference effects there is no reality before measurement, but by excluding such effects the system gets a real meaning already before measurement.

quant-ph↗

arXiv2012

The phase of Hidden Momentum in Aharonov-Bohm solenoid effect

It is shown that the phase of the hidden momentum in Aharonov-Bohm (AB) solenoid effect is equal in magnitude to the phase of the electron but with opposite sign. The phase of the hidden momentum is equal to that obtained by the energy of interference calculated in our previous paper (J.Opt.Soc.Am. B 17, 2052 2000).

quant-ph↗

arXiv2011

Complemetarity of Phases in Aharonov-Bohm Solenoid Effect

In the present Note it is suggested that there should be a certain complementarity of phases between Aharonov-Bohm (AB) solenoid phase calculation on one part of the system and a phase calculation about another part of the physical system. Assuming a unique value for the function of the total system, after a complete circulation of the electron around the solenoid, the sum of these two phase changes should vanish. Such assumption leads to a compatibility relation between our previous calculations for the AB solenoid phase effect and that of the original calculation by AB.

quant-ph↗

arXiv2011

Soliton solutions of non-linear Schrodinger (NLS) and Korteweg de Vries (KdV) equations related to zero curvature in the x,t plane

Soliton solutions of non-linear NLS and KdV equations are related to compatibility condition between matrices M and H describing the movement of an auxilary function Psi in the x,t plane with a zero curvature condition. Non-linear equation for a function u is obtained by the compatibility equation where the matrix elements of M and H include only functions of u and its derivatives. By solving the equations of motion for Psi a soliton solution for u is obtained. Explicit calculations are made with two-dimensional and one-dimensional wave functions Psi for the NLS and KdV solitons, correspondingly.

nlin.SI↗

arXiv2011

Classical and Quantum Mechanical (QM) Effects in the One-Soliton solution of the EM Nonlinear Schrodinger (NLS) Equation

Propagation effects are analyzed for electromagnetic (EM) waves which satisfy the one-soliton non-linear Schrodinger (NLS) equation in a dispersive wave guide. The coupling between momentum and frequencies due to dispersion relation is treated by a coupled Hamiltonian-Momentum operator with equal-space commutation relations(CR). Kerr interactions in the soliton are treated. The classical solution of the one-soliton with possible quantum effects are analyzed. The integrability of nonlinear equations is related to compatibility-condition for scattering matrices and such relation is applied to the NLS equation.

quant-ph↗

arXiv2011

Energy dispersion relation for negative refraction (NR) materials

A general energy dispersion relation is developed for metamaterials having the negative-refraction (NR) property. It is shown that absorption effects are involved with NR phenomena, and the conditions under which NR occurs are discussed. Simple equations for NR are developed using Lorentzian models.

physics.optics↗

arXiv2010

The use of squeezed states and balanced homodyne for detecting gravitational waves

The possibility of using squeezed states and balanced homodyne detection of gravitational waves is discussed. It is shown that the quantum noise due to high laser intensities in Michelson interferometer for gravitational waves detection can be reduced by sending squeezed vacuum states to the 'dark' port of the interferometer. The present analysis describes photon statistics measurements effects related to quadrature balanced homodyne detection showing the advantage of using this scheme for detecting gravitational waves.

gr-qc↗

arXiv2009

A proposal for investigating three-body forces in Aharonov-Bohm sytems

Although there is no force on the electron in Aharonov-Bohm solenoid effect, the electron exerts a force on the solenoid related to the inequality of action and reaction forces of two subsystems in three-system configuration. The AB phase which is related to the force exerted by the electron on the solenoid . The momentum changes of the mechanical oscillator are equal in magnitude and opposite in sign to the changes in the momentum of the em fields. It is proposed to investigate momentum changes of "micro" bodies producing magnetic fields in AB systems which will clarify the nature of these effects. The problem of magnetic fields shielded from the electron wave packet is also discussed.

quant-ph↗

arXiv2009

Geomeric phases in Quantum Mechanics

Various phenomena related to geometric phases in quantum mechanics are reviewed and explained by analyzing some examples.The concepts of 'parallelism' ,'connections' and 'curvatures' are applied to Aharonov-Bohm (AB) effect, to U(1)phase rotation, to SU(2) phase rotation and to holonomic quantum computation (HQC). The connections in Schrodinger equations are treated by two alternative approaches. Implementation of HQC is demonstrated by the use of 'dark states' including detailed calculations with the connections, for implementing the quantum gates. 'Anyons' are related to the symmetries of the wave functions,in a two-dimensional space, and the use of this concept is demonstrated by analyzing an example taken from the field of Quantum Hall effects.

quant-ph↗