PerspectivePhysics

A twist on the Majorana fermion

See allHide authors and affiliations

Science  21 Jul 2017:
Vol. 357, Issue 6348, pp. 252-253
DOI: 10.1126/science.aao0793

You are currently viewing the summary.

View Full Text

Summary

All superconductors are characterized by an energy gap, a range of energies in which excitations are forbidden. However, the recently discovered class of topological superconductors (TSs) has a unique distinguishing feature: The boundary of a TS hosts gapless states called Majorana modes. The term Majorana stems from similarities with the unusual particles proposed by Ettore Majorana in his seminal 1937 paper (1). However, although Majorana's particles are fermions that are their own antiparticles, Majorana modes are composite quantum mechanical states, with distinct and perhaps even more intriguing properties. On page 294 of this issue, He et al. (2) provide compelling evidence for the observation of chiral Majorana modes at the boundary of a two-dimensional TS.