Measurement of energy relaxation in quantum Hall edge states utilizing quantum point contacts

TL;DR

This paper presents a novel method using quantum point contacts to measure energy relaxation in quantum Hall edge states, distinguishing between tunneling and energy exchange processes, and revealing short-distance relaxation mechanisms.

Contribution

Introduces a new technique employing quantum point contacts to probe local electronic states and energy relaxation in quantum Hall edge states, validating it through experimental measurements.

Findings

Relaxation lengths measured are consistent with previous studies.

Energy exchange without tunneling can cause short-distance relaxation.

Method effectively distinguishes between tunneling and energy exchange processes.

Abstract

We demonstrated a method to probe local electronic states and energy relaxation in quantum Hall edge states utilizing quantum point contacts. We evaluated relaxation lengths in two cases; first, with electron tunneling, and second, only with energy exchange without tunneling between edge states. The results were consistent with previous experiments and validated our method with quantum point contacts. We applied this method to measure the energy relaxation length around a hotspot in quantum Hall regimes and revealed the possible short-distance relaxation process to be the relaxation due to energy exchange between edge states without electron tunneling.