Tuesday, November 24 at 11 a.m. EST
Daniel Rodan-Legrain
PhD candidate
Physics
The recent observation of superconductivity and correlated insulating states in ‘magic-angle’ twisted bilayer graphene (MATBG) featuring nearly-flat bands at twist angles close to 1.1 degrees presents a highly tunable two-dimensional material platform capable of behaving as a metal, an insulator, or a superconductor. Local electrostatic control over these phases may enable the creation of versatile quantum devices that were previously not achievable in other single material platforms.
In this talk, Rodan-Legrain will introduce MATBG as a new arena to investigate strongly correlated physics. He will then show how they can exploit the electrical tunability of MATBG to engineer Josephson junctions and tunneling transistors all within one material, defined solely by electrostatic gates. The research group's multi-gated device geometry offers complete control over the Josephson junction, with the ability to independently tune the weak link, barriers, and tunneling electrodes. Utilizing the intrinsic bandgaps of MATBG, they also demonstrate monolithic edge tunneling spectroscopy within the same MATBG devices and measure the energy spectrum of MATBG in the superconducting phase.
Furthermore, by inducing a double barrier geometry, the devices can be operated as a single-electron transistor, exhibiting Coulomb blockade. These MATBG tunneling devices, with versatile functionality encompassed within a single material, may find applications in graphene-based tunable superconducting qubits, on-chip superconducting circuits, and electromagnetic sensing in next-generation quantum nanoelectronics.
Attendees can join and participate in the series via Zoom. Meeting ID#: 860 986 455.