Variational Study on a Dissipative Two-Level System  

作　　者：朱维婷 任清褒 陈庆虎 

机构地区：[1]Department of Physics, Lishui University, Lishui 323000 [2]Department of Physics, Zhejiang University, Hangzhou 310027 [3]Department of Physics, Zhejiang Normal University, ffinhua 321004

出　　处：《Chinese Physics Letters》2008年第9期3129-3131,共3页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 10574107, and the Natural Science Foundation of Zhejiang Province under Grant No Y606128.

摘　　要：A new variational approach is proposed to study the ground-state of a two-level system coupled to a dispersionless pbonon bath. By the extended coherent state, where the more phonon correlations are easily incorporated, we can obtain very accurate ground state energy and the tunnelling reduction factor in all regime of tunnelling matrix element δ0 and coupling parameter s. The relative difference between the present ones and those by exact numerical diagonalization is less then 0.001%. In addition, some simple analytical results are given in the limits of δ0/s → 0 and ∞.A new variational approach is proposed to study the ground-state of a two-level system coupled to a dispersionless pbonon bath. By the extended coherent state, where the more phonon correlations are easily incorporated, we can obtain very accurate ground state energy and the tunnelling reduction factor in all regime of tunnelling matrix element δ0 and coupling parameter s. The relative difference between the present ones and those by exact numerical diagonalization is less then 0.001%. In addition, some simple analytical results are given in the limits of δ0/s → 0 and ∞.

关 键 词：the power-law exponents PRECIPITATION durative abrupt precipitation change 

分 类 号：TN752[电子电信—电路与系统]