Open AccessSpin coherent-state transformation and analytical solutions of ground-state based on variational-method for spin-Bose models
Author(s) -
Xingguo Yang,
Hai-Bin Xue,
J.-Q. Liang
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.114205
Subject(s) - physics , ground state , transformation (genetics) , bose–einstein condensate , quantum mechanics , variational method , spin (aerodynamics) , canonical transformation , atom (system on chip) , coherent states , state (computer science) , quantum , quantum electrodynamics , mathematics , biochemistry , chemistry , algorithm , computer science , gene , embedded system , thermodynamics
We present a variational method for the ground-state solutions of the spin-Bose models by means of the spin coherent-state transformation. For the Jaynes-Cummings (J-C) models with and without the rotating-wave approximation, the ground-state energies obtained by this method are in perfect agreement with the results from numerical diagonalization in the whole region of the coupling between a light field and an atom. The present variational-method can be directly used to solve the ground-state energies of the Dicke models with arbitrary atom-numbers and furoher study the quantum phase transition; while the variational-method based on the Holstein-Primakoff transformation is only valid in principle for the thermodynamic limit with the atom-number tending to infinity.