Magnetoresistance and electric current oscillations induced by geometry in a two-dimensional quantum ring

TL;DR

This paper studies how the geometry of a two-dimensional quantum ring influences magnetoresistance and electric current oscillations, revealing new ways to optimize quantum transport by adjusting device shape.

Contribution

It introduces the impact of controlled conical geometry on charge transport and oscillations in a quantum ring, highlighting geometry as a tuning parameter.

Findings

Magnetoresistance oscillations depend on curvature intensity.

Charge transport exhibits oscillations influenced by geometry.

Geometry tuning offers an alternative method for device optimization.

Abstract

In this work, we investigate the effects of a controlled conical geometry on the electric charge transport through a two-dimensional quantum ring weakly coupled to both the emitter and the collector. These mesoscopic systems are known for being able to confine highly mobile electrons in a defined region of matter. In particular, we consider a GaAs device having an average radius of $800\hspace{0.05cm}\text{nm}$ in different regimes of subband occupation at non-zero temperature and under the influence of a weak and uniform background magnetic field. Using the adapted Landauer formula for the resonant tunneling and the energy eigenvalues, we explore how the modified surface affects the Van-Hove conductance singularities, the magnetoresistance interference patterns resulting from the Aharonov-Bohm oscillations of different frequencies and the charge transport when an electric potential is applied in the terminals of the device. Magnetoresistance and charge current oscillations depending only on the curvature intensity are reported, providing a new feature that represents an alternative way to optimize the transport through the device by tuning its geometry.