Abstract

Topological insulators in proximity to a superconductor have been predicted 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.