Separation of spin and charge in paired spin-singlet quantum Hall states

Abstract

We propose a series of paired spin-singlet quantum Hall states, which exhibit a separation of spin and charge degrees of freedom. The fundamental excitations over these states, which have filling fraction $\ensuremath{\nu}=2/(2m+1)$ with m an odd integer, are spinons (spin-$\frac{1}{2}$ and charge zero) or fractional holons (charge $\ifmmode\pm\else\textpm\fi{}1/(2m+1)$ and spin zero). The braid statistics of these excitations are non-Abelian. The mechanism for the separation of spin and charge in these states is topological: spin and charge excitations are liberated by binding to a vortex in a p-wave pairing condensate. We briefly discuss related, Abelian spin-singlet states and possible transitions.