Instability of Abrikosov lattice due to nonanalytic core reconstruction   of vortices in Bosonic superfluids
  We study the impact of the non-analytic reconstruction of vortex cores on static vortex structures in weakly coupled superfluids. We show that in rotating two-dimensional systems, the Abrikosov vortex lattice is unstable to vortex core deformation: Each zero of the wave function becomes a cut of finite length. The directors characterizing the orientations of the cuts are themselves ordered in superstructures due either to surface effects or to interaction with shear deformations of the lattice (spiral structure). Similar instability may be also observable in clean superconducting films. 
Avraham Klein, Oded Agam, and Igor L. Aleiner
cond-mat.other cond-mat.quant-gas cond-mat.supr-con