Surface transport coefficients for three-dimensional topological superconductors
We argue that surface spin and thermal conductivities of three-dimensional topological superconductors are universal and topologically quantized at low temperature. For a bulk winding number ν, there are |ν| “colors” of surface Majorana fermions. Localization corrections to surface transport coefficients vanish due to time-reversal symmetry (TRS). We argue that Altshuler-Aronov interaction corrections vanish because TRS forbids color or spin Friedel oscillations. We confirm this within a perturbative expansion in the interactions, and to lowest order in a large-|ν| expansion. In both cases, we employ an asymptotically exact treatment of quenched disorder effects that exploits the chiral character unique to two-dimensional, time-reversal-invariant Majorana surface states.
Xie, Hong-Yi, Chou, Yang-Zhi and Foster, Matthew S.. "Surface transport coefficients for three-dimensional topological superconductors." Physical Review B, 91, no. 2 (2015) American Physical Society: 024203. http://dx.doi.org/10.1103/PhysRevB.91.024203.