From theory to confidence: building trust in twistronics models

Authors: Diamond Light Source
Co-authored by industrial partner: No

Type: Science Highlight

State: Published (Approved)
Published: February 2024
Diamond Proposal Number(s): 20573 , 28919 , 32737

Abstract: A single sheet of graphene, composed of a single layer of carbon atoms in a hexagonal pattern, is a semimetal. However, adding a second sheet of graphene, twisted at a slight angle to the first, can give rise to very different electronic properties, depending on the angle. At the 'magic' angle of about 1.1°, for example, a twisted bilayer sheet of graphene is a superconductor. The same effect is seen in other 2D materials, giving rise to a new field of study - twistronics - seeking to both understand and exploit the relationship between twist angles and novel electronic properties. In work recently published in Nano Letters, researchers from the University of Warwick and the National Graphene Institute at the University of Manchester used spatially-resolved angle-resolved photoemission spectroscopy (ARPES) on Diamond's I05 beamline to study the twist-dependent band structure of twisted-bilayer, monolayer-on-bilayer, and double-bilayer graphene. Their results show good agreement between experimental measurements and theoretical simulations, confirming that the models can be used to explore the electronic band structure and emergent transport and optical properties of twisted-few-layer graphenes.

Journal Keywords: graphene; twistronics; moiré; flat band; angle-resolved photoemission spectroscopy

Subject Areas: Materials, Physics

Instruments: I05-ARPES

Added On: 29/02/2024 10:34

Discipline Tags:

Physics Hard condensed matter - structures Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES) Nano ARPES