PIRSA:14050017

Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators

Tang, E. (2014). Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators. Perimeter Institute. https://pirsa.org/14050017

Tang, Evelyn. Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators. Perimeter Institute, May. 01, 2014, https://pirsa.org/14050017 

          @misc{ pirsa_PIRSA:14050017,
            doi = {10.48660/14050017},
            url = {https://pirsa.org/14050017},
            author = {Tang, Evelyn},
            keywords = {},
            language = {en},
            title = {Strain Induces Helical Flat Band \& Interface Superconductivity in Topological Crystalline Insulators},
            publisher = {Perimeter Institute},
            year = {2014},
            month = {may},
            note = {PIRSA:14050017 see, \url{https://pirsa.org}}
          }

Evelyn Tang Rice University

DOI 10.48660/14050017
Collection
Talk Type Conference

Abstract

Topological crystalline insulators in IV-VI compounds host novel topological surface states, that at low energy, consist of multi-valley massless Dirac fermions. We show that strain generically acts as an effective gauge field on these Dirac fermion surface states and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict this is naturally realized in IV-VI semiconductor heterostructures due to the spontaneous formation of a misfit dislocation array at the interface, where the zero-energy Landau orbitals form a nearly flat band. We propose that the high density of states of this topological flat band gives rise to the experimentally observed interface superconductivity in IV-VI semiconductor multilayers at temperatures that are unusually high for semiconductors, and explains its non-BCS dependence on dislocation array period.