arXiv subjects

Jian Qi Shen

Publications and source records attributed to Jian Qi Shen.

At least 37 records · Page 2Linked to original sources

arXiv2004

Dual curvature tensors and dynamics of gravitomagnetic matter

Gravitomagnetic charge that can also be referred to as the {\it dual mass} or {\it magnetic mass} is the topological charge in gravity theory. A gravitomagnetic monopole at rest can produce a stationary gravitomagnetic field. Due to the topological nature of gravitomagnetic charge, the metric of spacetime where the gravitomagnetic matter is present will be nonanalytic. In this paper both the dual curvature tensors (which can characterize the dynamics of gravitational charge/monopoles) and the antisymmetric gravitational field equation of gravitomagnetic matter are presented. We consider and discuss the mathematical formulation and physical properties of the dual curvature tensors and scalar, antisymmetric source tensors, dual spin connection (including the low-motion weak-field approximation), dual vierbein field as well as dual current densities of gravitomagnetic charge. It is shown that the dynamics of gravitomagnetic charge can be founded within the framework of the above dual quantities. In addition, the dual relationship between the dynamical theories of gravitomagnetic charge (dual mass) and gravitoelectric charge (mass) is also taken into account in the present paper.

gr-qc↗

arXiv2004

Maintenance of Coherence and Polarization Evolution in a Supersymmetric Multiphoton Model

The elimination of decoherence of two-state quantum systems interacting with a thermal reservoir through an external controllable driving field is discussed in the present paper. The restriction equation with which the external controllable driving field should agree will be derived. Based on this, we obtain the time-development equation of the off-diagonal elements of density operator in the supersymmetric multiphoton two-state quantum systems, which is helpful for studying the polarization evolution in this two-state quantum model.

quant-ph↗

arXiv2004

Hyperbolical geometric quantum phase and topological dual mass

In this note we show the existence of the hyperbolical geometric quantum phase that is different from the ordinary trigonometric geometric quantum phase. Gravitomagnetic charge (dual mass) is the gravitational analogue of magnetic monopole in Electrodynamics; but, as will be shown here, it possesses more interesting and significant features, {\it e.g.}, it may constitute the dual matter that has different gravitational properties compared with mass. In order to describe the space-time curvature due to the topological dual mass, we construct the dual Einstein's tensor. Further investigation shows that gravitomagnetic potentials caused by dual mass are respectively analogous to the trigonometric and hyperbolic geometric phase. The study of the geometric phase and dual mass provides a valuable insight into the time evolution of quantum systems and the topological properties in General Relativity.

physics.class-ph↗

arXiv2004

The interaction between graviton spin and gravitomagnetic fields

This note is devoted to the detailed mathematical treatment of the coupling of graviton spin to gravitomagnetic fields. The expression (i.e., $\sim g_{0m}\dot{g}_{0n}(\partial_{m}g_{0n}-\partial_{n}g_{0m})$) for the graviton spin-gravitomagnetic (S-G) coupling in the Lagrangian/Hamiltonian density of the weak gravitational fields is presented in this note.

gr-qc↗

arXiv2004

Introduction to the theory of left-handed media

This paper is devoted to investigating the physically interesting optical and electromagnetic properties, phenomena and effects of wave propagation in the negative refractive index materials, which is often referred to as the {\it left-handed media} in the literature. This paper covers a wide range of subjects and related topics of left-handed media such as many mathematical treatment of fundamental effects ({\it e.g.}, the reflection and the refraction laws on the interface between LH and RH media, the group velocity and energy density in dispersive materials, the negative optical refractive index resulting from a moving regular medium, the reversal of Doppler effect in left-handed media, the reversal of Cerenkov radiation in left-handed media, the optical refractive index of massive particles and physical meanings of left-handed media, the anti-shielding effect and negative temperature in left-handed media, {\it etc.}), and their some applications to certain areas ({\it e.g.}, three kinds of compact thin subwavelength cavity resonators (rectangular, cylindrical, spherical) made of left-handed media, the photon geometric phases due to helicity inversions inside a periodical fiber made of left-handed media, {\it etc.}).

cond-mat.mtrl-sci↗

arXiv2004

Three kinds of compact thin subwavelength cavity resonators containing left-handed media: rectangular, cylindrical, spherical

In the present paper we investigate the restriction conditions for three kinds of cavity resonators ({\it i.e.}, the rectangular, cylindrical, spherical resonators). It is shown that the layer of materials with negative optical refractive indices can act as a phase compensator/conjugator, and thus by combining such a layer with another layer made of the regular medium one can obtain a so-called compact thin subwavelength cavity resonator.

cond-mat.mtrl-sci↗

arXiv2004

A scheme of measurement of quantum-vacuum geometric phases in the noncoplanar fibre system

We study the quantum-vacuum geometric phases resulting from the vacuum fluctuation of photon fields in Tomita-Chiao-Wu noncoplanar curved fibre system, and suggest a scheme to test the potential existence of such vacuum effect. Since the signs of the quantum-vacuum geometric phases of left- and right- handed (LRH) circularly polarized light are just opposite, the total geometric phases at vacuum level is inescapably absent in the fibre experiments performed previously by other authors. By using the present approach where the fibre made of gyroelectric media is employed, the quantum-vacuum geometric phases of LRH light cannot be exactly cancelled, and may therefore be achieved test experimentally.

quant-ph↗

arXiv2004

Comoving suppression mechanism and cosmological constant problem

In this paper, we assume that the observer is fixed in a comoving frame of reference with $g_{00}=\fracλΛ$, where $λ$ and $Λ$ denote the comoving parameter and the cosmological constant, respectively. By using the {\it comoving suppression mechanism} and {\it Mach's principle} (the latter of which is used to determine the comoving parameter $λ$), we calculate the vacuum energy density of quantum fluctuation field in the above-mentioned comoving frame of reference. It is shown that in such a comoving frame of reference, the cosmological constant will greatly decrease by many orders of magnitude (if Mach's principle is applied to this calculation, then it will be shown that $Λ$ is reduced by about 120 orders of magnitude). Additionally, we briefly discuss the related topics such as the varying observed speed of light ($\frac{{\rm d}c}{{\rm d}t}={\mathcal O}(10^{-9}{\rm m/s}^{2})$) and the mystery of anomalous acceleration ($\sim 10^{-9}{\rm m/s}^{2}$) acquired by the Pioneer 10/11, Galileo and Ulysses spacecrafts.

gr-qc↗

arXiv2003

Motion of a charged particle in the magnetic dipole field

This note discusses the motion of a charged particle in the magnetic dipole field and a modified Barut's lepton mass formula. It is shown that a charged particle in the magnetic dipole filed has no bound states, which means that Barut's lepton mass formula may have no physical basis.

quant-ph↗

arXiv2003

Negative optical refractive index resulting from a moving regular medium

The optical refractive index of a moving regular medium is calculated by using the Lorentz transformation in this note. It is shown that in some velocity region of medium moving relative to the initial frame K, the moving medium may possess a negative index of refraction measured by the observer fixed at the frame of reference K.

physics.class-ph↗

arXiv2003

An approach to the time-dependent Jaynes-Cummings model without the rotating wave approximation

This report presents an approach to the exact solutions of the time-dependent Jaynes-Cummings (J-C) model without the rotating wave approximation (RWA). It is shown that there is a squeezing-operator unitary transformation for relating the J-C model without RWA and the one with RWA. Thus by using an appropriate squeezing unitary transformation, the time-dependent J-C model without RWA can be transformed into the one with RWA that has been exactly solved previously, and based on this one can readily obtain the exact solutions of the time-dependent Jaynes-Cummings (J-C) model without RWA. The approach presented here also shows that we can treat these two kinds of time-dependent J-C models (both with and without RWA) in a unified way.

quant-ph↗

arXiv2003

The connection between conformal group and quantum states of photons

This note is concerned with the connections between the conformal group and the quantum states of photons. It is shown that there exist analogies between the photonic quantum states and the conformal group, namely, the time-development operator (with a free Hamiltonian), displacement and squeezing operators of the vacuum state corresponds to the dilatation, translation, proper Lorentz transformations, respectively, and that the three quantum states of photons ({\it i.e.}, Fock state, coherent state and squeezed state) in quantum optics thus bear some analogy to the above three transformations in the conformal group. Based on this comparison, we argue by analogy that if the phase transformation operators acting on a vacuum state (hence the Fock state, coherent state and squeezed state are generated) are truly exactly analogous to the conformal transformations, then a fourth quantum state of photons (referred to as the {\it conformal state}), which corresponds to the {\it special conformal} transformation (acceleration transformation) and will therefore be of special physical interest, can be suggested.

physics.optics↗

arXiv2003

The self-induced charge current in the experiments detecting photon rest mass

This note considers two related topics regarding the {\it self-induced charge current} in the experiments detecting photon rest mass: (i) the effective rest mass, $(0.3\sim 1)\times 10^{-54}$ Kg, of photons arising from the ions in the secondary cosmic ray is compared to Luo {\it et al.}'s new upper limit on photon rest mass ($1.2\times 10^{-54}$ Kg); (ii) there are two main classes of experiments to detect photon rest mass based respectively on the Ampère-Maxwell-Proca equation and the Lagrangian (or Hamiltonian) density of electromagnetically interacting system.

physics.class-ph↗

arXiv2003

Comment on "Solutions of the Schrödinger equation for the time-dependent linear potential''

We show that the solution obtained by Bekkar {\it et al.} in their comment [Phys. Rev. A {\bf 68}, 016101 (2003)] on Guedes's work of solving the quantum system with a time-dependent linear potential is still {\it not} the {\it general} one of the Schrödinger equation. It is concluded that Bekkar {\it et al.}'s solution (corresponding to the linear Lewis-Riesenfeld invariant) and our solution (corresponding to the quadratic-form Lewis-Riesenfeld invariant) presented here will constitute together a complete set of solutions (general solutions) of the time-dependent Schrödinger equation of the system under consideration.

quant-ph↗

arXiv2003

Solutions of the Schrödinger equation for the time-dependent linear potential

By making use of the Lewis-Riesenfeld invariant theory, the solution of the Schrödinger equation for the time-dependent linear potential corresponding to the quadratic-form Lewis-Riesenfeld invariant $I_{\rm q}(t)$ is obtained in the present paper. It is emphasized that in order to obtain the general solutions of the time-dependent Schrödinger equation, one should first find the complete set of Lewis-Riesenfeld invariants. For the present quantum system with a time-dependent linear potential, the linear $I_{\rm l}(t)$ and quadratic $I_{\rm q}(t)$ (where the latter $I_{\rm q}(t)$ cannot be written as the squared of the former $I_{\rm l}(t)$, {\it i.e.}, the relation $I_{\rm q}(t)= cI_{\rm l}^{2}(t)$ does not hold true always) will form a complete set of Lewis-Riesenfeld invariants. It is also shown that the solution obtained by Bekkar {\it et al.} more recently is the one corresponding to the linear $I_{\rm l}(t)$, one of the invariants that form the complete set. In addition, we discuss some related topics regarding the comment [Phys. Rev. A {\bf 68}, 016101 (2003)] of Bekkar {\it et al.} on Guedes's work [Phys. Rev. A {\bf 63}, 034102 (2001)] and Guedes's corresponding reply [Phys. Rev. A {\bf 68}, 016102 (2003)].

quant-ph↗

arXiv2003

The Connection Between Density Matrix Method, Supersymmetric Quantum Mechanics and Lewis-Riesenfeld Invariant Theory

This paper is concerned with the connection between density matrix method, supersymmetric quantum mechanics and Lewis-Riesenfeld invariant theory. It is shown that these three formulations share the common mathematical structure: specifically, all of them have the invariant operators which satisfies the Liouville-Von Neumann equation and the solutions to the time-dependent Schrödinger equation and/or Schrödinger eigenvalue equation can be constructed in terms of the eigenstates of the invariants.

quant-ph↗

arXiv2003

A Supplement: on the Quantum-vacuum Geometric Phases

Three related topics on the quantum-vacuum geometric phases in a noncoplanarly curved optical fiber is presented: (i) a brief review: the investigation of vacuum effect and its experimental realization; (ii) the sequence of ideas of geometric phases in the fiber; (iii) three derivations of effective Hamiltonian that describes the wave propagation of photon field in a curved fiber.

quant-ph↗

arXiv2003

An Experimental Realization of Quantum-vacuum Geometric Phases by Using the Gyrotropic-medium Optical Fiber

The connection between the quantum-vacuum geometric phases (which originates from the vacuum zero-point electromagnetic fluctuation) and the non-normal product procedure is considered in the present Letter. In order to investigate this physically interesting geometric phases at quantum-vacuum level, we suggest an experimentally feasible scheme to test it by means of a noncoplanarly curved fiber made of gyrotropic media. A remarkable feature of the present experimental realization is that one can easily extract the nonvanishing and nontrivial quantum-vacuum geometric phases of left- and/or right- handed circularly polarized light from the vanishing and trivial total quantum-vacuum geometric phases.

quant-ph↗