Dissipation Induced Flat Bands

TL;DR

This paper demonstrates that dissipation in fermionic systems can induce long-lived, dispersionless flat bands through engineered bath coupling, with potential for experimental realization in 2D materials on superconductors.

Contribution

It introduces a novel mechanism where dissipation creates flat bands in fermionic systems via a dark space protected by symmetry.

Findings

Flat bands can be realized through dissipation in fermionic systems.

These flat bands are protected and long-lived due to symmetry.

The mechanism is robust across various models and conditions.

Abstract

Flat bands are an ideal environment to realize unconventional electronic phases. Here, we show that fermionic systems with dissipation governed by a Bloch Lindbladian can realize dispersionless bands for sufficiently strong coupling to an appropriately engineered bath. These flat bands emerge in a "dark space" of the system-environment coupling and are long-lived by virtue of symmetry protection from dissipation. We exhibit the robustness of this mechanism for general one and two band models with and without spin, and discuss conditions for their experimental realization such as in a 2D material on a superconducting substrate.