46 citations · 132 across the 9 of their papers we have counts for
9 papers
Macroscopic quantum states, quantum phase transition for three-level atoms in an optical cavity -- Gauge principle and non-Hermitian Hamiltonian
Ni Liu, Xinyu Jia, J. -Q. Liang
We study in this paper the quantum phase transition (QPT) from normal phase (NP) to superradiant phase (SP) for three-level atoms in a single-mode optical cavity for both Hermi…
Quantum mechanics of inverted potential well -- Hermitian Hamiltonian with imaginary eigenvalues, quantum-classical correspondence
Ni Liu, J. -Q. Liang
We in this paper study the quantization of a particle in an inverted potential well. The Hamiltonian is Hermitian, while the potential is unbounded below. Classically the particle…
Imaginary eigenvalues of Hermitian Hamiltonian with an inverted potential well and transition to the real spectrum at exceptional point by a non-Hermitian interaction
Ni Liu, Meng Luo, J. -Q. Liang
We in this paper study the hermiticity of Hamiltonian and energy spectrum for the SU(1; 1) systems. The Hermitian Hamiltonian can possess imaginary eigenvalues in contrast with the…
Entanglement Dynamics for Two Spins in an Optical Cavity---Field Interaction Induced Decoherence and Coherence Revival
Xue-Min Bai, Chun-Ping Gao, Jun-Qi Li +2
We in this paper study quantum correlations for two neutral spin-particles coupled with a single-mode optical cavity through the usual magnetic interaction. Two-spin entangled stat…
Collective atomic-population-inversion and stimulated radiation for two-componentBose-Einstein condensate in an optical cavity
Xiuqin Zhao, Ni Liu, J-Q Liang
In this paper we investigate the ground-state properties and related quantum phase transitions for the two-component Bose-Einstein condensate in a single-mode optical cavity. Apart…
Dicke Phase Transition and Collapse of Superradiant Phase in Optomechanical Cavity with Arbitrary Number of Atoms
Xiuqin Zhao, Ni Liu, Xuemin Bai +1
We in this paper derive the analytical expressions of ground-state energy, average photon-number, and the atomic population by means of the spin-coherent-state variational method f…
Nonlinear Atom-Photon Interaction Induced Population Inversion and Inverted Quantum Phase Transition of Bose-Einstein Condensate in an Optical Cavity
Xiuqin Zhao, Ni Liu, J-Q Liang
In this paper we explore the rich structure of macroscopic many-particle quantum states for Bose- Einstein condensate in an optical cavity with the tunable nonlinear atom-photon in…
Analytical ground state for the Jaynes-Cummings model with the ultrastrong coupling
Yuanwei Zhang, Gang Chen, Lixian Yu +3
We present a generalized variational method to analytically obtain the ground-state properties of the unsolvable Jaynes-Cummings model with the ultrastrong coupling. An explicit ex…
Light-shift-induced quantum phase transitions of a Bose-Einstein condensate in the optical cavities
Ni Liu, Jinling Lian, Jie Ma +4
In this paper we reveal the rich ground-state properties induced by the strong nonlinear atom-photon interaction, which has been found in the recent experiment about a Bose-Einstei…