Topological superconductivity in a Bi2Te3/NbSe2 heterostructure:A review

Topological superconductors carry globally protected gapless boundary excitations, which are robust under local perturbations, and thus exhibit both fundamental and applicational importance. An unconventional pairing with p-wave symmetry, such as a nontrivial topology in the superconductor’s wavefunction, is required to generate a non-zero Berry phase. Until now, the BiTe/2 H–NbSeheterostructure has proven to be a practical way to realize a topological superconductor in real materials. This complex system, where odd numbers of spin-momentum locked Dirac cone surface states on the topological insulator BiTebecome superconducting, induced by the proximate effect from the underlying s-wave superconductor 2 H–NbSe, realizes an effective two-dimensional(2 D) spinless p+ i ptopological superconductor. In this review article, we summarize the recent experimental progress of the successful synthesis of BiTe/2 H–NbSeheterostructures using molecular beam epitaxy, determining the thickness limit of the heterostructure, detecting the long thought Majorana quasiparticle inside a magnetic vortex core state by means of scanning tunneling microscopy and demonstration of the unique spatial and spin properties of a Majorana zero mode.