Electron-Phonon Decoupling in Two Dimensions

TL;DR

This paper explores how electron-phonon decoupling can occur in suspended two-dimensional films, leading to bistability in electron temperature, with potential experimental signatures in nonlinear current-voltage behavior.

Contribution

It identifies conditions for electron-phonon decoupling and bistability in 2D suspended films, highlighting regimes where this phenomenon is experimentally observable.

Findings

Bistability manifests as hysteretic jumps in I-V characteristics.

Decoupling is feasible in systems with Arrhenius conductivity.

Unlikely in materials with Mott or Efros-Shklovskii hopping.

Abstract

In order to observe many-body localisation in electronic systems, decoupling from the lattice phonons is required, which is possible only in out-of-equilibrium systems. We show that such an electron-phonon decoupling may happen in suspended films and it manifests itself via a bistability in the electron temperature. By studying the electron-phonon cooling rate in disordered, suspended films with two-dimensional phonons, we derive the conditions needed for such a bistability, which can be observed experimentally through hysteretic jumps of several orders of magnitude in the nonlinear current-voltage characteristics. We demonstrate that such a regime is achievable in systems with an Arrhenius form of the equilibrium conductivity, while practically unreachable in materials with Mott or Efros-Shklovskii hopping.