3,852 research outputs found
Interaction-mediated surface state instability in disordered three-dimensional topological superconductors with spin SU(2) symmetry
We show that arbitrarily weak interparticle interactions destabilize the
surface states of 3D topological superconductors with spin SU(2) invariance
(symmetry class CI), in the presence of non-magnetic disorder. The conduit for
the instability is disorder-induced wavefunction multifractality. We argue that
time-reversal symmetry breaks spontaneously at the surface, so that
topologically-protected states do not exist for this class. The
interaction-stabilized surface phase is expected to exhibit ferromagnetic
order, or to reside in an insulating plateau of the spin quantum Hall effect.Comment: v2: 5+3 pages, 1 figure; expanded introduction, added background on
topological superconductors and multifractality, technical details relegated
to sup info (published version
Quench-induced Floquet topological p-wave superfluids
Ultracold atomic gases in two dimensions tuned close to a p-wave Feshbach
resonance were expected to exhibit topological superfluidity, but these were
found to be experimentally unstable. We show that one can induce a topological
Floquet superfluid if weakly interacting atoms are brought suddenly close
("quenched") to such a resonance, in the time before the instability kicks in.
The resulting superfluid possesses Majorana edge modes, yet differs from a
conventional Floquet system as it is not driven externally. Instead, the
periodic modulation is self-generated by the dynamics.Comment: 5+5 pages, 2 figure
- …