Seminars

Due to their large bulk band gap, bismuthene, antimonene, and arsenene on a SiC substrate offer intriguing new opportunities for room-temperature quantum spin Hall (QSH) applications. We show that for experimentally relevant armchair nanoribbons, we find a distinct behavior of the gap induced in the QSH edge states for out-of-plane magnetic fields (a few meV) versus in-plane magnetic fields (negligible gap) which is the hallmark of their topological origin. Further, we predict experimentally testable fingerprints of this behavior in the LDOS and in ballistic magnetotransport.

Abstract: We consider a system consisting of several correlated monoatomic layers sandwiched between two metallic leads. In addition to the local Hubbard interaction we also take the long-range Coulomb interaction into account, which causes electronic charge reconstruction in the correlated layers, as well as in the leads. The non-equilibrium situation is driven by applying a bias voltage to the leads. We investigate the steady-state behavior of the system for different parameters (bias voltage, interaction strength, hybridization strength between leads and the correlated...

Abstract: Far-infrared techniques played a crucial role in the experimental validation of Bardeen–Cooper–Schrieffer (BCS) theory and they continue to provide fundamental information about condensate, quasiparticle and vortex behaviour in both equilibrium and non-equilibrium states of superconductors.
In this talk, we will focus on the response of thin superconducting NbN films. We confirmed that their equilibrium conductivity follows the conventional BCS theory. Application of a dc magnetic field induces vortices in the films, which leads to qualitatively different responses,...