Stacking two-dimensional atomic crystals or the application of external potentials to such crystals, can radically change their electronic properties. In particular, it is possible to engineer conditions leading to the creation of weakly dispersing (flat) energy bands, where the quenched kinetic energy provides propitious conditions for the emergence of correlated electronic states such as Mott insulators, superconductors, charge density waves etc. This talk will focus on two such examples: twisted graphene bilayers that develop a flat band at a “magic” twist-angle of ~ 10, and buckled graphene layers in which a periodically modulated pseudo-magnetic field creates a post-graphene material with flat electronic bands.
Jiang, Y. et al. Charge order and broken rotational symmetry in magic-angle twisted bilayer graphene. Nature 573, (2019) 91
G. Li, et al, Observation of Van Hove singularities in twisted graphene layers, Nature Physics, 6 (2010) 109
Eva Y. Andrei is a Board of Governors Chaired professor in the department of Physics and Astronomy at Rutgers University. She is an experimental condensed matter physicist recognized for her work on low dimensional electron systems including graphene, two-dimensional electrons on helium, magnetically induced Wigner crystallization in semiconductor heterojunctions and vortices in superconductors.
Andrei is a fellow of the National Academy of Sciences, the American Academy of Arts and Sciences, the American Physical Society and the American Association for the Advancement of Science. She is the recipient of the Medal of Physics awarded by the French Commission of Atomic Energy and of the Rutgers Board of Trustees Award for Excellence in Research. She has served as Chair of the AAAS Physics division, and is currently serving in the chair-line of the APS division of condensed matter physics.