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∼10K 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.
@article{arxiv.2012.03570,
title = {Superballistic electron flow through a point contact in a Ga[Al]As heterostructure},
author = {Lev V. Ginzburg and Carolin Gold and Marc P. Röösli and Christian Reichl and Matthias Berl and Werner Wegscheider and Thomas Ihn and Klaus Ensslin},
journal= {arXiv preprint arXiv:2012.03570},
year = {2021}
}