Delta-T noise for fractional quantum Hall states at different filling factor

TL;DR

This paper investigates the delta-T noise in fractional quantum Hall states, providing exact solutions and universal expressions that enhance understanding of transport properties in strongly interacting systems.

Contribution

It offers an exact solution for delta-T noise in hybrid fractional quantum Hall junctions and derives a universal formula linking it to equilibrium noise for all filling factors.

Findings

Exact solution for delta-T noise in hybrid junctions.

Universal analytical expression relating delta-T noise to equilibrium noise.

Insights into transport properties of strongly interacting quantum Hall systems.

Abstract

The current fluctuations due to a temperature bias, i.e. the delta-$T$ noise, allow one to access properties of strongly interacting systems which cannot be addressed by the usual voltage-induced noise. In this work, we study the full delta-$T$ noise between two different fractional quantum Hall edge states, with filling factors $(\nu_L,\nu_R)$ in the Laughlin sequence, coupled through a quantum point contact and connected to two reservoirs at different temperatures. We are able to solve exactly the problem for all couplings and for any set of temperatures in the specific case of an hybrid junction $(1/3,1)$. Moreover, we derive a universal analytical expression which connects the delta-$T$ noise to the equilibrium one valid for all generic pairs $(\nu_L,\nu_R)$ up to the first order in the temperature mismatch. We expect that the linear term can be accessible in nowadays experimental set-ups. We describe the two opposite coupling regimes focusing on the strong one which correspond to a non-trivial situation. Our analysis on delta-$T$ noise allows us to better understand the transport properties of strongly interacting systems and to move toward more involved investigation concerning the statistics and scaling dimension of their emergent excitations.