Out-of-equilibrium criticalities in graphene superlattices
Abstract
In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy whereas the filled bands underneath contribute little to conduction. Here we describe a very different regime in which carrier distribution in graphene and its superlattices is shifted so far from equilibrium that the filled bands start playing an essential role, leading to a critical-current behavior. The criticalities develop upon the velocity of electron flow reaching the Fermi velocity. Key signatures of the out-of-equilibrium state are current-voltage characteristics resembling those of superconductors, sharp peaks in differential resistance, sign reversal of the Hall effect, and a marked anomaly caused by the Schwinger-like production of hot electron-hole plasma. The observed behavior is expected to be common for all graphene-based superlattices.
Keywords
Cite
@article{arxiv.2106.12609,
title = {Out-of-equilibrium criticalities in graphene superlattices},
author = {Alexey I. Berdyugin and Na Xin and Haoyang Gao and Sergey Slizovskiy and Zhiyu Dong and Shubhadeep Bhattacharjee and P. Kumaravadivel and Shuigang Xu and L. A. Ponomarenko and Matthew Holwill and D. A. Bandurin and Minsoo Kim and Yang Cao and M. T. Greenaway and K. S. Novoselov and I. V. Grigorieva and K. Watanabe and T. Taniguchi and V. I. Fal'ko and L. S. Levitov and R. Krishna Kumar and A. K. Geim},
journal= {arXiv preprint arXiv:2106.12609},
year = {2022}
}
Comments
22 pages, 11 figures