Publication Date

7-7-2021

Department

Ames Laboratory; Physics and Astronomy

Campus Units

Ames Laboratory, Physics and Astronomy

OSTI ID+

1806220

Report Number

IS-J 10550

DOI

10.1038/s41467-021-24480-3

Journal Title

Nature Communications

Volume Number

12

First Page

4180

Abstract

Magic-angle twisted bilayer graphene has emerged as a powerful platform for studying strongly correlated electron physics, owing to its almost dispersionless low-energy bands and the ability to tune the band filling by electrostatic gating. Techniques to control the twist angle between graphene layers have led to rapid experimental progress but improving sample quality is essential for separating the delicate correlated electron physics from disorder effects. Owing to the 2D nature of the system and the relatively low carrier density, the samples are highly susceptible to small doping inhomogeneity which can drastically modify the local potential landscape. This potential disorder is distinct from the twist angle variation which has been studied elsewhere. Here, by using low temperature scanning tunneling spectroscopy and planar tunneling junction measurements, we demonstrate that flat bands in twisted bilayer graphene can amplify small doping inhomogeneity that surprisingly leads to carrier confinement, which in graphene could previously only be realized in the presence of a strong magnetic field.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Included in

Physics Commons

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