Quantum Café is CCQ’s ongoing seminar series: open to all bona fide members of the greater NYC scientific community and held every second week, Quantum Café presents a series of informal, highly interactive talks, typically by external speakers, which present the most interesting recent developments and open questions in our field.
Title: The Phases of WTe2
Abstract: Multifunctional quantum materials are important for realizing critical phenomena, manifesting novel switching behavior, and producing robust interface physics. The multifunctionality of topological two-dimensional (2D) materials is exemplified by WTe2 which is a type-II Weyl semimetal with non-saturating magnetoresistance in its bulk, transforming into a superconductor under hydrostatic pressure, or transforming into a quantum spin hall insulator (QSHI) in its monolayer limit, which can then be tuned to a superconductor with electrostatic gating. In many of these transformations, the tuning of the carrier density and crystal structure has been shown to play an important role. I will discuss our progress in producing two non-monotonic changes in electronic structure of WTe2 upon in-situ surface manipulation, realizing an interface field effect as a pathway for tuning behavior of 2D materials.