Bulletin of the American Physical Society
APS March Meeting 2021
Volume 66, Number 1
Monday–Friday, March 15–19, 2021; Virtual; Time Zone: Central Daylight Time, USA
Session J50: Straintronics: Tuning the electronic properties of 2D materials by strain engineering
3:00 PM–6:00 PM,
Tuesday, March 16, 2021
Sponsoring
Unit:
DCMP
Chair: Eric Hudson, Pennsylvania State University
Abstract: J50.00002 : Evidence of flat bands and correlated states in buckled graphene superlattices*
3:36 PM–4:12 PM
Live
Presenter:
Jinhai Mao
(School of physical Sciences, University of Chinese Academy of Sciences)
Author:
Jinhai Mao
(School of physical Sciences, University of Chinese Academy of Sciences)
bands in bilayer graphene for certain ‘magic’ angles of twist between the orientations of the two layers. The quenched kinetic energy in these flat bands promotes electron–electron interactions and facilitates the emergence of strongly correlated phases, such as superconductivity and correlated insulators. However, the very accurate fine-tuning required to obtain the magic angle in twisted-bilayer graphene poses challenges to fabrication and scalability. Here I present an alternative route to creating flat bands that does not involve fine-tuning. Using scanning tunnelling microscopy and spectroscopy, together with numerical simulations, we demonstrate that graphene monolayers placed on an atomically flat substrate can be forced to undergo a buckling transition, resulting in a periodically modulated pseudo-magnetic field, which in turn creates a ‘post-graphene’ material with flat electronic bands. When we introduce the Fermi level into these flat bands using electrostatic doping, we observe a pseudogap-like depletion in the density of states, which signals the emergence of a correlated state. This buckling of two-dimensional crystals offers a strategy for creating other superlattice systems and,in particular, for exploring interaction phenomena characteristic of flat bands.
J. Mao et al "Evidence of flat bands and correlated states in buckled graphene superlattices"
Nature 584 (2020) 215
*We acknowledge support from the DOE (DOE-FG02-99ER45742; E.Y.A., Y.J.), the Gordon and Betty Moore Foundation (GBMF9453; E.Y.A.), the National Key R&D Program of China (2019YFA0307800, 2018YFA0305800; J.M.), the Beijing Natural Science Foundation (Z190011; J.M.)
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700