Tunable transmission via quantum state evolution in oval quantum dots

TL;DR

This paper investigates how the shape of oval quantum dots influences electron transmission, revealing tunable conductance properties affected by geometry and magnetic fields, with implications for quantum device design.

Contribution

It demonstrates that the transmission in oval quantum dots can be controlled via shape and magnetic field, highlighting the role of interference and decoupling mechanisms.

Findings

Transmission spectra show periodic resonances.

Weak magnetic fields significantly alter conductance.

Robustness against disorder is observed.

Abstract

We explore the quantum transmission through open oval shaped quantum dots. The transmission spectra show periodic resonances and, depending on the geometry parameter, a strong suppression of the transmission for low energies. Applying a weak perpendicular magnetic field changes this situation drastically and introduces a large conductance. We identify the underlying mechanisms being partially due to the specific shape of the oval that causes a systematic decoupling of a substantial number of states from the leads. Importantly a pairwise destructive interference of the transmitting states is encountered thereby leading to the complete conductance suppression. Coupling properties and interferences can be tuned via a weak magnetic field. These properties are robust with respect to the presence of disorder in the quantum dot.