Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators
APA
Tang, E. (2014). Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators. Perimeter Institute. https://pirsa.org/14050017
MLA
Tang, Evelyn. Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators. Perimeter Institute, May. 01, 2014, https://pirsa.org/14050017
BibTex
@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}} }
Rice University
Talk Type
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.