Giant boost of the quantum metric in disordered one dimensional flat band systems

TL;DR

This paper reveals that disorder can significantly enhance quantum transport in one-dimensional flat band systems due to a singular behavior of the quantum metric, challenging traditional views on disorder effects.

Contribution

It uncovers the giant boost of the quantum metric in disordered 1D flat band systems and links it to enhanced conductivity at low state densities.

Findings

Disorder can dramatically increase conductivity in flat band systems.

Quantum metric singularity underpins the giant boost in transport.

Potential implications for boosting critical temperatures in superconductors.

Abstract

It is a well known fact, that the disorder has its most dramatic effects on the conventional quantum transport in one dimensional systems. In flat band (FB) systems, it is revealed that the conductivity at the FB energy is robust against the disorder and can even be tremendously boosted. Furthermore, challenging our understanding of the physical phenomena, the giant increase occurs in the limit of low FB states density. The singular behaviour of the quantum metric of the FB eigenstates is found to be at the heart of these unexpected and puzzling features. Our findings should have interesting fallout for other physical systems, and may as well open up engineering strategies to boost the critical temperature in two dimensional superconducting FB materials.