论文标题
快速加扰器是好的热浴吗？
Are fast scramblers good thermal baths?
论文作者
论文摘要
Sachdev-Ye-Kitaev（Syk $ _ {4} $）模型引起了人们对其快速争夺性能和仅由温度设定的热效率的关注。在这项工作中，我们询问SYK $ _ {4} $型号是否也是一个很好的热浴的问题，从某种意义上说，它允许系统耦合到它进行热化。我们通过考虑$ n $随机非相互作用的系统的动力学来解决这个问题，该系统耦合到Syk $ _ {4} $ BATH和$ m $ Majorana fermions，我们使用Keldysh技术在$ \ gg gg n \ gg 1 $中固定的技术解决。我们将这种非平衡设置与传统的浴室进行比较，由自由度的自由度制成，并具有连续的频谱。我们表明，SYK $ _ {4} $ BATH在弱耦合下对系统的热效率更高，因为其在低频下的状态密度增强，而在强的系统池耦合下，两种类型的环境都会增加相似的热量时间尺度。
The Sachdev-Ye-Kitaev (SYK$_{4}$) model has attracted attention for its fast scrambling properties and its thermalization rate that is set only by the temperature. In this work we ask the question of whether the SYK$_{4}$ model is also a good thermal bath, in the sense that it allows a system coupled to it to thermalize. We address this question by considering the dynamics of a system of $N$ random non-interacting Majorana fermions coupled to an SYK$_{4}$ bath with $M$ Majorana fermions that we solve with Keldysh techniques in the limit of $M\gg N\gg 1$. We compare this nonequilibrium setting with a conventional bath made of free non-interacting degrees of freedom with a continous spectrum. We show that the SYK$_{4}$ bath is more efficient in thermalising the system at weak coupling, due to its enhanced density of states at low frequency, while at strong system-bath couplings both type of environments give rise to a similar time scale for thermalisation.
