Surface state transport in double-gated and magnetized topological insulators with hexagonal warping effects.

We explore the scattering of Dirac electrons in a double-gated topological insulator in the presence of magnetic proximity effects and warped surface states. It is found that a magnetic field can shift the Dirac cone in momentum space and deform the constant-energy contour, or opens up a band gap at the Dirac point, depending on the magnetization orientation. The double gate voltage induces quantum wells and/or quantum barriers on the surface of topological insulators, generating surface resonant tunnelling states.

Controlling the thermoelectric effect by mechanical manipulation of the electron's quantum phase in atomic junctions.

The thermoelectric voltage developed across an atomic metal junction (i.e., a nanostructure in which one or a few atoms connect two metal electrodes) in response to a temperature difference between the electrodes, results from the quantum interference of electrons that pass through the junction multiple times after being scattered by the surrounding defects.

Gate-controlled valley transport and Goos-Hänchen effect in monolayer WS.

Based on a Dirac-like Hamiltonian and coherent scattering formalism, we study the spin-valley transport and Goos-Hänchen-like (GHL) effect of transmitted and reflected electrons in a gated monolayer WS. Our results show that the lateral shift of spin-polarized electrons is strongly dependent on the width of the gated region and can be positive or negative in both Klein tunneling and classical motion regimes. The absolute values of the lateral displacements at resonance positions can be considerably enhanced when the incident angle of electrons is close to the critical angle.

Electrical conductance and structure of copper atomic junctions in the presence of water molecules.

We have investigated Cu atomic contacts in the presence of H2O both experimentally and theoretically. The conductance measurements showed the formation of H2O/Cu junctions with a fixed conductance value of around 0.1 G0 (G0 = 2e(2)/h).