QDev/NBIA Condensed Matter Theory Seminar: Carlo Beenakker

Majorana fermions in a quantum spin Hall insulator

Topological insulators in proximity to a superconductor have beenpredicted to support Majorana zero-modes: midgap states with identical creation and annihilation operators and non-Abelian braiding statistics, that are presently under intense scrutiny. The conducting edge of a quantum spin Hall insulator (a quantum well with an inverted band gap) seems like an ideal system to search for these elusive particles in a transport experiment: Only a single mode propagates in each direction along the edge, unaffected by disorder since backscattering of these helical modes is forbidden by time-reversal symmetry. We discuss the prospects for the detection of Majoranas as a short-term application, and braiding as a longer term perspective.