2019 journal article
Conductance nonreciprocity on the surface of a topological insulator with magnetic electrodes
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 128, 196–201.
Asymmetric electrical conductance is theoretically demonstrated on the surface of a topological insulator (TI) in the limit of infinitesimally small forward and reverse biases between two spin selective electrodes. The discontinuous behavior relies on the spin-momentum interlocked nature of TI surface electrons together with the resulting imbalance in the coupling coefficients between the electrodes and TI surface states. The analysis is based on a transmission matrix model that, in combination with a phenomenological treatment for the diffusive limit, accounts for both ballistic and scattered paths simultaneously. With the estimated conductance asymmetry over a factor of 10, implementations in the ratchet-like applications and low-voltage rectification circuits are potentially practicable.