PAMS Seminar: "Cloning of Dirac Electrons in Graphene/SiC Heterostructure" by Dr. Guang Bian

PAMS Seminar: "Cloning of Dirac Electrons in  Graphene/SiC Heterostructure" by Dr. Guang Bian
Date and time
4:00 PM - 5:00 PM, March 24, 2022
Description

Dr. Guang Bian
Department of Physics & Astronomy
University of Missouri

Abstract:

Tuning interaction between Dirac states in graphene has attracted great interest because it modifies the spectra of the two-dimensional electron system and, consequently, gives rise to novel condensed-matter phases such as superconductors, Mott insulators, Wigner crystals and quantum anomalous Hall insulators. For example, emergent superconductivity occurs in twisted bilayer graphene at magic angles due to the enhanced correlation between Dirac fermions in the two graphene layers. In this work, we report a new way to engineer the band structure of graphene, namely, cloning Dirac states by the perturbation of substrate potential. We grow the graphene epitaxially on 6H-SiC substrate. The SiC surface potential exerts an incommensurate perturbation to the graphene Dirac bands, resulting in the duplication of Dirac states at different locations in the momentum space. The clone of the Dirac states has been observed in our angle-resolved photoemission spectroscopy (ARPES) experiments. We perform theoretical modelling to illuminate this cloning mechanism and show the possibility of controllably modifying the electronic spectra of two-dimensional atomic crystals by varying the substrate parameters.

This seminar will be via Zoom.

Event sponsor
Admission

Free

Open to public, alumni, current students, faculty, future students, staff
Location
Zoom: 955 2509 1021