Ensslin, Klaus

Date:   Thursday, June 17, 2021
Time:   10:00
Place:   scheduled Zoom meeting
Host:    Lukas Novotny

Mind the gap in graphene: twisted and untwisted

Klaus Ensslin
ETH Zurich

Band gaps in semiconductors are crucial to confine charge carriers by split gates. This enables the realization of high quality quantum dots (or qubits) in GaAs and Si. Monolayer graphene has no bandgap. Bilayer graphene can have a bandgap in large vertical electric fields. In this talk we will show how this tunable bandgap can be used to confine charge carriers, build single and double dots, and explore charge, spin and valley qubits. Twisted graphene layers can give rise to novel correlated states, such as superconductors or insulators. We will show how twisting can be used to prepare single-particle gaps, realize correlated electron-hole states and build superconducting quantum devices, such as Josephson junctions.
This work was done in collaboration with Chuyao Tong, Rebekka Garreis, Annika Kurzmann, Carolin Gold, Veronika Stara, Hadrien Duprez, Corinna Burri, Peter Rickhaus, Fokko DeVries, Giulia Zheng, Elias Portoles, Petar Tomic, Shuiji Iwakiri and Thomas Ihn.