Sun Changpu

Idealization second quantization of composite particles

A practical method is developed to deal with the second quantization of the many-body system containing the composite particles. In our treatment, the modes associated with composite particles are regarded approximately as independent ones compared with those of unbound particles. The field operators of the composite particles thus arise naturally in the second quantization Hamiltonian. To be emphasized, the second quantization Hamiltonian has the regular structures which correspond clearly to different physical processes.

Hybrid Exciton-Polaritons in a Bad Microcavity Containing the Organic and Inorganic Quantum Wells

We study the hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells. The corresponding polariton states are given. The analytical solution and numerical result of the stationary spectrum for the cavity field are finished.

Momentum Transfer and Effect of Motion of Atomic Mass Centre on an Atom-Cavity System*

For a special -type atom with dark state, the problem of momentum transfer is discussed in detail. Effect of moving mass centre on atomic dynamics for various initial conditions is also studied. The numerical results show that the Doppler effect exercised by the motion of atomic mass centre can lead to the modified phenomenon of oscillation collapse and revival in the transition probability and the atomic population inversion.

APPROXIMATION THEORY OF OSCILLATING FACTOR SUPPRESSING AMPLITUDE IN QUANTUM PROCESS AND ITS APPLICATIONS

The oscillating factor suppressing amplitude approximation is proposed in this paper as a basic method to study the evolution of a quantum system. By making use of this method, not only the quantum adiabatic approximation is described again, but also both the higher-order corrections for the rotation wave approximation and the influences of other levels on two-level approximation can be analytically investigated with the explicit discussion for the quantitative conditions under which the two approximations hold.

Higher-order correction for rotating wave approximation, Rabi transformation, and its applications in the Jaynes-Cummings model

Taking into account the consistence of the quantum adiabatic approximation and the rotating wave approximation in essence, we propose a method to study the interaction between atom and radiation field in a quantized cavity systematically. By using the exact solution of Jaynes-Cummings model as the lowest-order approximation, the effect of high frequency terms on the dynamics of atom-cavity field system is studied analytically.

Fermion System with Quantum Group Symmetry and Usual Fermion Realizations of Slq (2)

The usual fermion realizations of quantum algebra slq (2) defining higher-dimensional representations are built in this letter. Using them, we construct a usual fermion system with quantum group symmetry of slq (2) as a q-deformation of the pairing correlation model in many-body problems. Its energy spectra are exactly solved out from the representation theory of slq (2).

Quantum Group Construction of Non-standard R-matrix for Yang-Baxter Equation

By taking the concept of weight conservation into account, new solutions of Yang-Baxter equation without spectral parameter are obtained through the non-standard R-matrix on the tensorial space V1/2 ⊗ Vj (j ≠ 1/2) in terms of the irreducible representation of the quantum universal enveloping algebra SLq (2). The non-standard R-matrix R1/2 1 is obtained in an explicit form for j = 1.

Classical analogues of quantum berry's phase

With the classical generalized harmonic oscillator as an example, we show that the analogues of the quantum Berrys phase can appear in the classical mechanic systems with adiabatically-changing parameters, which have the Schrodinger-type evolution equations. The corresponding guage structures are naturally induced in these systems.

High-order quantum berry's adiabatic phase and its observable effect

New high-order adiabatic approximate method is proposed for the study of non-adiabatic evolution of a quantum system with slowly-changing Hamiltonian. The corresponding high-order Berrys adiabatic phases are used to describe the transition from a state to another, and their observable effects in quantum interference experiment are pointed out.