Entanglement entropy and entanglement spectrum of triplet topological superconductors
Abstract
We analyze the entanglement entropy properties of a 2D pwave superconductor with Rashba spinorbit coupling, which displays a rich phasespace that supports nontrivial topological phases, as the chemical potential and the Zeeman term are varied. We show that the entanglement entropy and its derivatives clearly signal the topological transitions and we find numerical evidence that for this model the derivative with respect to the magnetization provides a sensible signature of each topological phase. Following the area law for the entanglement entropy, we systematically analyze the contributions that are proportional to or independent of the perimeter of the system, as a function of the Hamiltonian coupling constants and the geometry of the finite subsystem. For this model, we show that even though the topological entanglement entropy vanishes, it signals the topological phase transitions in a finite system. We also observe a relationship between a topological contribution to the entanglement entropy in a halfcylinder geometry and the number of edge states, and that the entanglement spectrum has robust modes associated with each edge state, as in other topological systems.
 Publication:

Journal of Physics Condensed Matter
 Pub Date:
 October 2014
 DOI:
 10.1088/09538984/26/42/425702
 arXiv:
 arXiv:1312.7782
 Bibcode:
 2014JPCM...26P5702O
 Keywords:

 Condensed Matter  Superconductivity;
 Condensed Matter  Strongly Correlated Electrons;
 Quantum Physics
 EPrint:
 9 pages, 8 figures