Talk by Anastasia Varlet, ETH Zürich, Switzerland Bilayer graphene (BLG) is a highly tunable material: the Fermi energy can be easily changed with an electric field and one can tune the band structure from un-gapped to gapped via the application of a displacement field D. In high quality samples, the low energy dispersion is not parabolic but exhibits trigonal warping, with the presence of 4 massless Dirac cones. Combining quality and high displacement fields leads to a situation where the Lifshitz transition, the change in the Fermi contour topology, is brought to an energy range where it can be probed experimentally. In this talk, we will focus on explaining the details of the band structure of bilayer graphene and highlight the importance of its quality to probe the details of the band structure. We will then explain how to get high quality bilayer graphene and conclude by showing Fabry-Pérot interference through a dual-gated bilayer graphene device, proving the high quality obtained. Finally, we will focus on the way to probe the Lifshitz transition in the same device using quantum Hall effect as a tool to reveal the different degeneracies of the band structure. --------------------- Co-workers: MH. Liu, M. Mucha-Kruczyński, V. Krueckl, D. Bischoff, P. Simonet, K. Richter, V. Fal'ko, T. Ihn & K. Ensslin. References: Phys. Rev. Lett. 113, 116601 (2014) and Phys. Rev. Lett. 113, 116602 (2014).

This event is part of the eventgroup INT Talks

Homepage
https://www.int.kit.edu/events.php

Speaker
Anastasia Varlet, ETH Zürich

ETH Zürich, Switzerland
Nanophysics group http://www.nanophys.ethz.ch/index.p

Organizer
Dr. Romain Danneau
Institute of Nanotechnology (INT)
Karlsruhe Institute of Technology (KIT)
Eggenstein-Leopoldshafen
Tel: 0721/608-28896
Mail: romain danneau ∂does-not-exist.kit edu

Targetgroup
Interested / Everyone