反旋转波相互作用对非平衡自旋玻色模型热输运性质的影响

The effect of dissipative counter-rotating wave terms on thethermal transport properties of the non-equilibrium spin boson model

随着实验技术的发展,量子系统中已经实现了强和超强自旋-腔、自旋-环境相互作用。很大一类光学腔和耗散环境可以用波色热库描述。在强系统-热库耦合条件下,之前适用于弱耦合条件下的旋波近似失效,需要考虑系统-热库的反旋转波相互作用对系统动力学演化和稳态行为的影响。使用正则变换和全计数统计方法,研究系统-热库反旋转波相互作用对热输运性质的影响。结果表明:在弱耦合情况下采用旋波近似时,稳态热流、噪声功率以及热力学不确定关系随温度单调增大。强耦合情况,反旋转波相互作用下,以上物理量呈非单调性:先增大后减小。在弱耦合情况下采用旋波近似时,热力学不确定关系与耦合强度无关。强耦合情况,反旋转波相互作用下,热力学不确定关系随着耦合强度的增大而减小,向热力学不确定关系的下限逼近。说明量子相干性有助于提高量子热机的性能,使其优于经典热机。

Aided with a canonical transformation and full-counting statistics,this paper calculates the thermal transport properties of non-equilibrium spin boson model and studies the effect of the dissipative counter-rotating wave term on the thermal transport properties of this model.The steady state heat flow,noise power,and thermodynamic uncertainty relation with temperature for different coupling strengths are plotted based on the computational results.The results show that:(1)Under the effect of dissipative inverse rotating waves,the steady-state heat flow,noise power,and thermodynamic uncertainty relation of the strong coupling case show obvious non-monotonous behaviors:firstly,they increase to the maximum value with the increase of temperature and then decrease with the increase of temperature.(2)Without the dissipative counter-rotating wave terms,the thermodynamic uncertainty relationship is independent of the coupling strength.However,after accounting for the effect of the dissipative counter-rotating wave terms,the thermodynamic uncertainty relationship decreases with the increase of coupling strength,approaching the lower bound.