Tang, E. (2014). Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators. Perimeter Institute for Theoretical Physics. https://pirsa.org/14050017
MLA
Tang, Evelyn. Strain Induces Helical Flat Band & Interface Superconductivity in Topological Crystalline Insulators. Perimeter Institute for Theoretical Physics, May. 01, 2014, https://pirsa.org/14050017
BibTex
@misc{ scivideos_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 for Theoretical Physics},
year = {2014},
month = {may},
note = {PIRSA:14050017 see, \url{https://scivideos.org/index.php/pirsa/14050017}}
}
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.
