Out-of-equilibrium criticalities in graphene superlattices

Alexey Berdyugin, Na Xin, Haoyang Gao, Sergey Slizovskiy, Zhiyu Dong, Shubhadeep Bhattacharjee, Piranavan Kumaravadivel, Shuigang Xu, Leonid Ponomarenko, Matthew Holwill, Denis Bandurin, Minsoo Kim, Yang Cao, Mark Greenaway, Konstantin Novoselov, Irina Grigorieva, K Watanabe, T Taniguchi, Vladimir Fal'ko, Leonid LevitovRoshan Krishna Kumar, Andre Geim

Research output: Contribution to journalArticlepeer-review

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 that resemble 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 to all graphene-based superlattices.
Original languageEnglish
Pages (from-to)430-433
Number of pages4
JournalScience
Volume375
Issue number6579
DOIs
Publication statusPublished - 28 Jan 2022

Keywords

  • Graphene
  • Superlattices
  • Schwinger
  • particle creation
  • High bias
  • Nonlinear behavior

Research Beacons, Institutes and Platforms

  • National Graphene Institute

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