Magnetic barrier induced conductance fluctuations in quantum wires

TL;DR

This paper investigates how localized magnetic fields affect conductance in quantum wires, revealing temperature-dependent fluctuations caused by wave interference effects.

Contribution

It demonstrates the impact of magnetic barriers on conductance fluctuations and provides simulation-based insights into their origin from wave interference.

Findings

Conductance fluctuations are observed as a function of magnetic barrier amplitude.

Fluctuations are temperature dependent and visible up to 10 K.

Simulations suggest fluctuations originate from wave function interferences.

Abstract

Quasi-ballistic semiconductor quantum wires are exposed to localized perpendicular magnetic fields, also known as magnetic barriers. Pronounced, reproducible conductance fluctuations as a function of the magnetic barrier amplitude are observed. The fluctuations are strongly temperature dependent and remain visible up to temperatures of about 10 K. Simulations based on recursive Green functions suggest that the conductance fluctuations originate from parametric interferences of the electronic wave functions which experience scattering between the magnetic barrier and the electrostatic potential landscape.