Ultracold quantum wires with localized losses: many-body quantum Zeno effect

TL;DR

This paper investigates how localized particle losses in a one-dimensional interacting fermion system lead to a many-body quantum Zeno effect, suppressing particle emission at the Fermi level and altering the momentum distribution.

Contribution

It introduces a non-equilibrium model showing the many-body quantum Zeno effect in a gapless 1D system, using three complementary theoretical approaches.

Findings

Loss probability is strongly renormalized near the Fermi momentum.

Particle emission at the Fermi level is suppressed.

Momentum distribution exhibits a peak near the Fermi momentum.

Abstract

We study a one-dimensional system of interacting spinless fermions subject to a localized loss, where the interplay of gapless quantum fluctuations and particle interactions leads to an incarnation of the quantum Zeno effect of genuine many-body nature. This model constitutes a non-equilibrium counterpart of the paradigmatic Kane-Fisher potential barrier problem, and it exhibits strong interaction effects due to the gapless nature of the system. As a central result, we show that the loss probability is strongly renormalized near the Fermi momentum as a realization of the quantum Zeno effect, resulting in a suppression of the emission of particles at the Fermi level. This is reflected in the structure of the particle momentum distribution, exhibiting a peak close to the Fermi momentum. We substantiate these findings by three complementary approaches: a real-space renormalization group of a general microscopic continuum model, a dynamical Hartree-Fock numerical analysis of a microscopic model on a lattice, and a renormalization group analysis based on an effective Luttinger liquid description incorporating mode-coupling effects.