Thermal Properties of Interacting Bose Fields and Imaginary - Time Stochastic Differential Equations
Thermal Properties of Interacting Bose Fields and Imaginary - Time Stochastic Differential Equations
复制标题
相互作用玻色场和虚时间随机微分方程的热性质
DOI：
10.1209/epl/i1998-00411-9
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
H Germany
中科院分区：
文献类型：
--
作者：
L. Plimak;M. Fleischhauer;D. D. O. Physics;U. Auckland;Auckland;New Zealand Sektion Physik;L. Muenchen;Muenchen;H Germany
相互作用玻色子的松原绿色函数被表示为对应于线性时间随机微分方程的经典统计平均值。这使得直接数值模拟适用于研究玻色子在非微扰状态下的平衡量子性质。为了验证我们的结果，我们讨论了一个四次非谐振荡器作为一个相互作用的玻色气体的原型模型。导出了热态特征函数的解析表达式，并讨论了当振子频率为负时的Higgs型相变。
Matsubara Green's functions for interacting bosons are expressed as classical statistical averages corresponding to a linear imaginary-time stochastic differential equation. This makes direct numerical simulations applicable to the study of equilibrium quantum properties of bosons in the non-perturbative regime. To verify our results we discuss an oscillator with quartic anharmonicity as a prototype model for an interacting Bose gas. An analytic expression for the characteristic function in a thermal state is derived and a Higgs-type phase transition discussed, which occurs when the oscillator frequency becomes negative.