Spin splitting in open quantum dots

TL;DR

This paper investigates spin-splitting phenomena in small open quantum dots through combined theoretical and experimental approaches, revealing persistent conductance peak splitting linked to spin degeneracy lifting caused by electron interactions.

Contribution

It provides new insights into spin-splitting behavior in open quantum dots, highlighting the role of electron interactions in lifting spin degeneracy across a wide magnetic field range.

Findings

Pronounced conductance peak splitting persists over a wide magnetic field range.

Splitting is independent of magnetic field strength.

Lifting of spin degeneracy is related to electron interactions in the dot.

Abstract

We present results from a theoretical and experimental study of spin-splitting in small open lateral quantum dots (i.e. in the regime when the dot is connected to the reservoirs via leads that support one or more propagating modes). We demonstrate that the magnetoconductance shows a pronounced splitting of the conductance peaks (or dips) which persists over a wide range of magnetic fields (from zero field to the edge-state regime) and is virtually independent of magnetic field. A numerical analysis of the conductance and the dot eigenspectrum indicates that this feature is related to a lifting of the spin degeneracy in the corresponding closed dot associated with the interaction between electrons of opposite spin.