Conférencier: Sergey Frolov, Department of Physics and Astronomy, University of Pittsburgh

Abstract: Tunneling spectroscopy measurements on one-dimensional superconducting hyid materials have revealed signatures of Majorana fermions which are the edge states of a bulk topological superconducting phase. We couple strong spin-orbit semiconductor InSb nanowires to conventional superconductors (NbTiN, Al) to obtain additional signatures of Majorana fermions and to explore the magnetic-field driven topological phase transition. Specifically, we map out the phase diagram of the topological phase in the space of Zeeman energy and chemical potential, and investigate the apparent closing and re-opening of the superconducting gap. We investigate how the topological superconducting phase would manifest in finite size systems, by electrostatically splitting the wire into segments of varied length. By chaining up several segments of a nanowire, we are realizing a quantum simulator of the Kitaev chain with tunable on-site energies and couplings between the sites, a step towards quantum simulation with semiconductor nanostructures.

Bio: 1996-2000 B.S. in Physics and Mathematics, Moscow Institute of Physics and Technology, 2000-2005 Ph.D. in Physics, Van Harlingen group at the University of Illinois at Urbana-Champaign, 2005-2008 postdoc in Folk group at the University of British Columbia, 2008-2012 postdoc in Kouwenhoven group at Delft University of Technology, September 2012 assistant professor in Frolov group at the University of Pittsburgh.

For more information, you can consult Prof. Frolov's web

Cette conférence est présentée par le RQMP Versant Nord du Département de physique de l'Université de Montréal et de Génie physique de la Polytechnique.