Cancelled: Vidya Madhavan - University of Illinois at Urbana–Champaign

Mon, 04/15/2019 - 12:30pm
Pupin Hall Theory Center, 8th Floor
*The colloquium of Vidya Madhavan will be postponed to a later date (TBA)*
"Creating and measuring the elusive Majorana fermions"

Dirac discovered that every fundamental particle must also have a distinct anti-particle which has the opposite charge. When particles and anti-particles meet, they annihilate each other releasing energy.  In 1937, Ettore Majorana predicted the existence of a special class of particles where the particle and the anti-particle are identical.  However, with the possible exception of neutrinos, so far there are no known fundamental particles that belong to this class. Recently, the possible realization of these exotic Majorana fermions as quasiparticle excitations in in solids has created much excitement. While most studies have focused on Majorana bound states which can serve as topological qubits, more generally, akin to elementary particles, Majorana fermions can propagate and display linear dispersion. These excitations have not yet been directly observed, and can also be used for quantum information processing. This talk is focused on recent work in realizing Majorana mode in condensed matter systems. I will first describe in detail the conditions under which such states can be realized and what their signatures are. I will then show scanning tunneling microscopy data on 1D domain walls in a superconductor, which might potentially be first realization of dispersing Majorana states in 1D.

About the speaker

Vidya investigates fundamental problems in quantum materials where interactions between the spin, charge, and structural degrees of freedom lead to emergent phenomena. She uses the tools of scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), spin-polarized STM (SP-STM) and molecular beam epitaxy (MBE) to unravel the mysteries of complex systems at the atomic scale. Her group carries out challenging, high-risk experiments, wherein the possibility of discovering new phenomena is high. Her team's recent work has focused on STM studies of complex oxides and thin films of topological materials.

More details on Vidya's research can be found here.