Seminar
Tuesday, 11 October, 2011
Group Seminar LMU: Topology by Dissipation: Majorana Fermions in an Atomic Quantum Wire
Tuesday, 11.10.2011 10:00 a.m. (s.t.) in H107, Fakultät für Physik LMU
Dr. Sebastian Diehl, Quantum Optics Theory Group, University of Innsbruck
We discuss the emergence of topological phases in stationary states of engineered driven-dissipative dynamics. To set the stage, first the basic setting of quantum state engineering via dissipation in many-body systems of atomic bosons and fermions is sketched. Then we focus on a quantum wire of spinless atomic fermions in an optical lattice coupled to a bath. The key feature of the dissipative dynamics described by a Lindblad master equation here is the existence of Majorana edge modes, representing a non-local decoherence free subspace. We describe dissipative non-Abelian braiding operations within the Majorana subspace, and we illustrate the insensitivity to imperfections. Topological protection is granted by a nontrivial winding number of the system density matrix. We finally discuss possible preparation and detection schemes to reveal the Majorana physics.