Emergence of Interlayer Coherence in Twist-Controlled Graphene Double Layers

Kenneth A. Lin, Nitin Prasad, G. William Burg, Bo Zou, Keiji Ueno, Kenji Watanabe, Takashi Taniguchi, Allan H. MacDonald, and Emanuel Tutuc

Phys. Rev. Lett. 129, 187701 – Published 24 October 2022

Abstract

We report enhanced interlayer tunneling with reduced linewidth at zero interlayer bias in a twist-controlled double monolayer graphene heterostructure in the quantum Hall regime, when the top ( $ν_{T}$ ) and bottom ( $ν_{B}$ ) layer filling factors are near $ν_{T} = \pm 1 / 2, \pm 3 / 2$ and $ν_{B} = \pm 1 / 2, \pm 3 / 2$ , and the total filling factor $ν = \pm 1$ or $\pm 3$ . The zero-bias interlayer conductance peaks are stable against variations of layer filling factor, and signal the emergence of interlayer phase coherence. Our results highlight twist control as a key attribute in revealing interlayer coherence using tunneling.

Received 22 June 2022
Accepted 29 September 2022

DOI:https://doi.org/10.1103/PhysRevLett.129.187701

Physics Subject Headings (PhySH)

Josephson effect Landau levels Quantum fluids & solids Quantum transport

Boron nitride Graphene Twisted heterostructures

Shubnikov-de Haas effect

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Kenneth A. Lin ¹, Nitin Prasad ², G. William Burg¹, Bo Zou ³, Keiji Ueno⁴, Kenji Watanabe ⁵, Takashi Taniguchi⁶, Allan H. MacDonald ³, and Emanuel Tutuc ^1,*

¹Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA
²Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
³Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA
⁴Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
⁵Research Center for Functional Materials, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan
⁶International Center for Materials Nanoarchitectonics, National Institute of Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan