Superballistic electron flow through a point contact in a Ga[Al]As heterostructure

TL;DR

This paper reports on measurements of electron transport through point contacts in a Ga[Al]As heterostructure, revealing superballistic conductance exceeding the ballistic limit, consistent with viscous electron flow models.

Contribution

It demonstrates superballistic electron flow in a Ga[Al]As heterostructure, supporting viscous transport models and extending understanding of electron dynamics in high-mobility systems.

Findings

Conductance increases with temperature around 10 K.

Conductance exceeds the Sharvin ballistic limit at high densities.

Results align with viscous electron transport models.

Abstract

We measure electronic transport through point contacts in the high-mobility electron gas in a Ga[Al]As heterostructure at different temperatures and bulk electron densities. The conductance through all point contacts increases with increasing temperature in a temperature window around $T \sim 10 K$ for all investigated electron densities and point contact widths. For high electron densities this conductance exceeds the fundamental ballistic limit (Sharvin limit). These observations are in agreement with a viscous electron transport model and previous experiments in graphene.