Long-lived binary tunneling spectrum in a quantum-Hall Tomonaga-Luttinger liquid

TL;DR

This paper demonstrates the existence of long-lived non-equilibrium binary spectra in quantum Hall edge channels, consistent with Tomonaga-Luttinger liquid theory, and highlights their potential for long-distance information transport.

Contribution

It reports the experimental observation of persistent non-equilibrium spectra in quantum Hall edge channels, supporting the integrable Tomonaga-Luttinger liquid model in solid-state systems.

Findings

Binary spectrum persists over 5-10 μm without thermalization

Spectral features match predictions of Tomonaga-Luttinger liquid theory

Long-lived plasmons can carry information over long distances

Abstract

The existence of long-lived non-equilibrium states without showing thermalization, which has previously been demonstrated in time evolution of ultracold atoms, suggests the possibility of their spatial analogue in transport behavior of interacting electrons in solid-state systems. Here we report long-lived non-equilibrium states in one-dimensional edge channels in the integer quantum Hall regime. An indirect heating scheme in a counterpropagating configuration is employed to generate a non-trivial binary spectrum consisting of high- and low-temperature components. This unusual spectrum is sustained even after travelling 5 - 10 {\mu}m, much longer than the length for electronic relaxation (about 0.1 {\mu}m), without showing significant thermalization. This observation is consistent with the integrable model of Tomonaga-Luttinger liquid. The long-lived spectrum implies that the system is well described by non-interacting plasmons, which are attractive for carrying information for a long distance.