Institute for Theoretical Physics, University of Cologne, D-50937 Cologne, Germany.
HISKP, University of Bonn, 53115 Bonn, Germany.
Phys Rev Lett. 2019 Feb 1;122(4):040402. doi: 10.1103/PhysRevLett.122.040402.
An isolated quantum gas with a localized loss features a nonmonotonic behavior of the particle loss rate as an incarnation of the quantum Zeno effect, as recently shown in experiments with cold atomic gases. While this effect can be understood in terms of local, microscopic physics, we show that novel many-body effects emerge when nonlinear gapless quantum fluctuations become important. To this end, we investigate the effect of a local dissipative impurity on a one-dimensional gas of interacting fermions. We show that the escape probability for modes close to the Fermi energy vanishes for an arbitrary strength of the dissipation. In addition, transport properties across the impurity are qualitatively modified, similarly to the Kane-Fisher barrier problem. We substantiate these findings using both a microscopic model of spinless fermions and a Luttinger liquid description.
具有局域损耗的孤立量子气体表现出粒子损耗率的非单调行为，这是量子Zeno 效应的体现，最近在冷原子气体的实验中得到了证实。虽然这种效应可以用局部的微观物理来理解，但我们表明，当非线性无隙量子涨落变得重要时，会出现新的多体效应。为此，我们研究了局域耗散杂质对一维相互作用费米子气体的影响。我们表明，对于任意强度的耗散，费米能附近模式的逃逸概率为零。此外，杂质处的输运性质也被定性地改变，类似于 Kane-Fisher 势垒问题。我们使用无自旋费米子的微观模型和 Luttinger 液体描述来证实这些发现。
