Semiclassical gaps in the density of states of chaotic Andreev billiards.
Semiclassical gaps in the density of states of chaotic Andreev billiards.
复制标题
混沌安德列夫台球状态密度的半经典间隙。
DOI：
10.1103/physrevlett.104.027001
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发表时间：
2009
影响因子：
8.6
通讯作者：
K. Richter
中科院分区：
文献类型：
--
作者：
J. Kuipers;D. Waltner;C. Petitjean;G. Berkolaiko;K. Richter
超导体与混沌弹道量子点的连接导致了有趣的现象，最值得注意的是在其激发光谱中出现了硬能隙。在这里，我们对待这样一个Andreev台球半经典的状态密度表示的电子（和空穴）离开和返回超导体的经典轨迹。我们展示了经典轨道相关性如何导致硬间隙的形成，正如随机矩阵理论在可忽略的Escherfest时间τ {E}的限制下所预测的那样，以及有限的τ {E}的影响如何导致差距缩小。此外，对于中间tau{E}，我们预测在E=pi变体普朗克/2 pi/2 tau {E}以下的第二个间隙，这可能是tau{E}效应的最清晰的特征。
The connection of a superconductor to a chaotic ballistic quantum dot leads to interesting phenomena, most notably the appearance of a hard gap in its excitation spectrum. Here we treat such an Andreev billiard semiclassically where the density of states is expressed in terms of the classical trajectories of electrons (and holes) that leave and return to the superconductor. We show how classical orbit correlations lead to the formation of the hard gap, as predicted by random matrix theory in the limit of negligible Ehrenfest time tau{E}, and how the influence of a finite tau{E} causes the gap to shrink. Furthermore, for intermediate tau{E} we predict a second gap below E=pi variant Planck's/2pi/2tau{E} which would presumably be the clearest signature yet of tau{E} effects.