Effect of tilted magnetic field on magnetosubbands and conductance of bi-layer quantum wire

TL;DR

This paper theoretically investigates how tilted magnetic fields affect the energy subbands and conductance in bi-layer quantum wires, revealing potential for conductance switching and spin polarization.

Contribution

It introduces a detailed analysis of magnetic field effects on energy dispersion and conductance in bi-layer nanowires with symmetric and asymmetric potentials.

Findings

Conductance can jump or drop by several quanta under tilted magnetic fields.

Magnetic field influences intra-layer and inter-layer subband mixing.

Potential for generating spin-polarized currents via Zeeman effect.

Abstract

The single electron magnetotransport in a vertical bi-layer semiconductor nanowire made of InAlAs/InGaAs and AlGaAs/GaAs heterostructure is theoretically studied. The magnetic field is directed perpendicularily to the main (transport) axis of the quantum wire and both non-zero components of magnetic field, that is the transverse and the vertical ones, allow to change the magnitude of intra-layer and inter-layer subbands mixing, respectively. We analyze in detail the changes introduced to energy dispersion relation E(k) by strong titled magnetic field up to several teslas for a symmetric and an asymmetric confining potential in the growth direction. These calculated energy dispersion relations are thereafter used to show that the value of conductance of bi-layer nanowire may jump as well as drop by few conductance quanta when the Fermi energy is changed what in conjunction with spin Zeeman effect may give a moderately spin polarized current.