arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1503.08064cond-mat.stat-mech
收藏

一维和二维量子模型:猝灭和不可逆熵的标度

One and two-dimensional quantum models: quenches and the scaling of irreversible entropy

Shraddha Sharma, Amit Dutta

摘要:

利用基态量子保真度的标度关系,给出了当封闭量子系统的哈密顿量中的一个参数突然改变时,系统在绝对零度温度下的不可逆功(剩余能量)的最一般标度关系,并考虑了两个极限,即热敏感极限和热力学极限.然后,有人认为,在足够低的温度下,当系统最初是在吉布斯状态的热淬火所产生的不可逆熵,很可能会显示出类似的标度行为。为了说明这一命题,我们考虑零温度和热淬火在一个和两个维狄拉克哈密顿量的不可逆功和不可逆熵的精确估计确实是可能的。利用这些精确的结果,我们然后建立:(i)在零温度下的不可逆功确实显示了一个适当的标度在热力学极限;(ii)在零温度下的一维狄拉克模型的不可逆功的标度显示了对数校正的标度,这是一个边缘的情况下的签名。(iii)此外,值得注意的是,对数修正确实出现在所产生的熵的标度,如果温度足够低,而消失的高温。对于2D模型,没有发现出现这样的对数校正。

英文摘要:

Using the scaling relation of the ground state quantum fidelity, we propose the most generic scaling relations of the irreversible work (the residual energy) of a closed quantum system at absolute zero temperature when one of the parameters of its Hamiltonian is suddenly changed; we consider two extreme limits namely, the heat susceptibility limit and the thermodynamic limit. It is then argued that the irreversible entropy generated for a thermal quench at low enough temperature when the system is initially in a Gibbs state, is likely to show a similar scaling behavior. To illustrate this proposition, we consider zero-temperature and thermal quenches in one and two-dimensional Dirac Hamiltonians where the exact estimation of the irreversible work and the irreversible entropy is indeed possible. Exploiting these exact results, we then establish: (i) the irreversible work at zero temperature indeed shows an appropriate scaling in the thermodynamic limit; (ii) the scaling of the irreversible work in the 1D Dirac model at zero-temperature shows logarithmic corrections to the scaling which is a signature of a marginal situation. (iii) Furthermore, remarkably the logarithmic corrections do indeed appear in the scaling of the entropy generated if temperature is low enough while disappears for high temperatures. For the 2D model, no such logarithmic correction is found to appear.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑