Skyrmionic state and stable half-quantum vortices in chiralp-wave superconductors

Abstract

Observability of half-quantum vortices and skyrmions in $p$-wave superconductors is an outstanding open question. Under the most common conditions, fractional flux vortices are not thermodynamically stable in bulk samples. Here we show that in chiral $p$-wave superconductors, there is a regime where, in contrast, lattices of integer-flux vortices are not thermodynamically stable. Instead, skyrmions made of spatially separated half-quantum vortices are the topological defects produced by an applied external field.