Département de Physique, École Normale Supérieure/PSL Research University, CNRS, 24 rue Lhomond, 75005 Paris, France.
Institute of Theoretical Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
Phys Rev Lett. 2018 May 25;120(21):217206. doi: 10.1103/PhysRevLett.120.217206.
The singularities of the dynamical response function are one of the most remarkable effects in many-body interacting systems. However in one dimension these divergences only exist strictly at zero temperature, making their observation very difficult in most cold atomic experimental settings. Moreover the presence of a finite temperature destroys another feature of one-dimensional quantum liquids: the real space quasilong-range order in which the spatial correlation functions exhibit power-law decay. We consider a nonequilibrium protocol where two interacting Bose gases are prepared either at different temperatures or chemical potentials and then joined. We show that the nonequilibrium steady state emerging at large times around the junction displays edge singularities in the response function and quasilong-range order.
动力学响应函数的奇异性是多体相互作用系统中最显著的效应之一。然而，在一维空间中，这些发散仅在绝对零度下严格存在，这使得它们在大多数冷原子实验环境中很难被观察到。此外，有限温度的存在破坏了一维量子液体的另一个特征：实空间准长程有序，其中空间相关函数表现出幂律衰减。我们考虑一个非平衡协议，其中两个相互作用的玻色气体要么处于不同的温度要么处于不同的化学势，然后将它们连接起来。我们表明，在连接点附近的大时间的非平衡稳态中，响应函数和准长程有序中出现边缘奇异性。
