Energy bands, conductance and thermoelectric power for ballistic electrons in a nanowire with spin-orbit interaction

TL;DR

This paper investigates how spin-orbit interaction influences energy bands, conductance, and thermoelectric power in a ballistic nanowire, revealing effects of electron density, temperature, and confinement potential.

Contribution

It provides a detailed analysis of spin-orbit effects on nanowire properties considering realistic boundary conditions and confinement, highlighting differences from harmonic potential models.

Findings

Wider conductance plateaus with increased electron density.

Nonlinear transverse confinement eliminates pole-like conductance features.

Thermoelectric power increases linearly at low T and deviates at higher T.

Abstract

We calculated the effects of spin-orbit interaction (SOI) on the energy bands, ballistic conductance and the electron-diffusion thermoelectric power of a nanowire by varying the temperature, electron density and width of the wire. The potential barriers at the edges of the wire are assumed to be very high. A consequence of the boundary conditions used in this model is determined by the energy band structure, resulting in wider plateaus when the electron density is increased due to larger energy-level separation as the higher subbands are occupied by electrons. The nonlinear dependence of the transverse confinement on position with respect to the well center excludes the "pole-like feature" in the conductance which is obtained when a harmonic potential is employed for confinement. At low temperature, the electron diffusion thermoelectric power increases linearly with T but deviates from the linear behavior for large values of T.