Pairing instabilities in topological insulator quantum wells
Abstract
Topological insulator quantum wells with induced attractive interactions between electrons are candidate systems for the realization of vortex lattice states and incompressible quantum vortex liquids with fractional excitations. These phases depend on the formation of lowenergy spintriplet Cooper pairs in the quantum well, under the combined influence of the superconducting proximity effect and Rashba spinorbit coupling. We analyze, using the LandauGinzburg framework, the competition between different pairing channels stimulated by the proximity effect and argue that correlated phases of triplets are likely accessible by tuning the gate voltage. We perturbatively calculate the triplet pairing instability and show that it occurs at finite momenta. This yields a spatially inhomogeneous superconducting state, which is likely a vortex lattice of spin supercurrents. We discuss the phase diagram of topological insulator quantum wells tunable by the gate voltage.
 Publication:

Physical Review B
 Pub Date:
 March 2013
 DOI:
 10.1103/PhysRevB.87.104514
 arXiv:
 arXiv:1208.0608
 Bibcode:
 2013PhRvB..87j4514N
 Keywords:

 73.90.+f;
 73.21.Fg;
 74.25.Uv;
 74.45.+c;
 Other topics in electronic structure and electrical properties of surfaces interfaces thin films and lowdimensional structures;
 Quantum wells;
 Proximity effects;
 Andreev effect;
 SN and SNS junctions;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 13 pages, 6 figures