Topological spin Hall states, charged skyrmions, and superconductivity in two dimensions

Phys Rev Lett. 2008 Apr 18;100(15):156804. doi: 10.1103/PhysRevLett.100.156804. Epub 2008 Apr 16.


We study the properties of two dimensional topological spin Hall insulators which arise through spontaneous breakdown of spin symmetry in systems that are spin rotation invariant. Such a phase breaks spin rotation but not time reversal symmetry and has a vector order parameter. Skyrmion configurations in this vector order parameter are shown to have an electric charge that is twice the electron charge. When the spin Hall order is destroyed by condensation of Skyrmions superconductivity results. This may happen either through doping or at fixed filling by tuning interactions to close the Skyrmion gap. In the latter case the superconductor-spin Hall insulator quantum phase transition can be second order even though the two phases break distinct symmetries.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.