Orthogonality catastrophe and shock waves in a nonequilibrium Fermi gas.
Orthogonality catastrophe and shock waves in a nonequilibrium Fermi gas.
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非平衡费米气体中的正交灾难和冲击波。
DOI：
10.1103/physrevlett.97.246402
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发表时间：
2006
影响因子：
8.6
通讯作者：
Paul Wiegmann
中科院分区：
文献类型：
--
作者：
E. Bettelheim;A. Abanov;Paul Wiegmann
在无耗散费米气体中传播的半经典波包不可避免地进入“梯度突变”状态，在此状态下，最初平滑的波前发展出大梯度，并经历了戏剧性的冲击波现象。电子输运中的非线性效应是由于费米面处的电子谱的弯曲。它们可以通过局部电位的突然转换来探测。在平衡状态下，这个过程产生大量的粒子-空穴对，这一现象与正交性突变密切相关。我们研究了这一现象的非平衡状态的推广，并展示了如何正交突变治愈梯度突变，通过提供一个分散正则化机制。
A semiclassical wave packet propagating in a dissipationless Fermi gas inevitably enters a "gradient catastrophe" regime, where an initially smooth front develops large gradients and undergoes a dramatic shock-wave phenomenon. The nonlinear effects in electronic transport are due to the curvature of the electronic spectrum at the Fermi surface. They can be probed by a sudden switching of a local potential. In equilibrium, this process produces a large number of particle-hole pairs, a phenomenon closely related to the orthogonality catastrophe. We study a generalization of this phenomenon to the nonequilibrium regime and show how the orthogonality catastrophe cures the gradient catastrophe, by providing a dispersive regularization mechanism.