Detecting the Topological Superconductivity: Pseudo Kondo Resonance in the Induced p + ip Supreconducting Surface State of Topological Insulator

Topological superconductors, which can be classified due to the symmetries they respect, have
drawn enormous attention recently. However, unambiguous scheme to probe or distinguish different
types of topological superconductors are still in need. We propose that a quantum magnetic impurity
can uncover the nature of the hosting topological superconductors. We study the Kondo effect in
the surface state of a topological insulator (TI) in proximity to a s-wave superconductor, which
is known to be topological similar to the intrinsic p+ip superconductor as it effectively enjoys the
p + ip pairing symmetry due to the spin-momentum locking. It is found that the induced p + ip
superconductor in TI surface state is more similar to the conventional s-wave superconductor rather
than the intrinsic p + ip superconductor in terms of the impurity-induced states. Two distinctive
features are also identified. One is the pseudogapped hybridization function and the shrinking of the
Kondo region, the other is the emergence of an unusal pseudo Kondo singlet state (PKS), where the
local impurity is screened by a pseudo spin composed of true spin and orbital angular momentum
index.