Probing the microscopic structure of bound states in quantum point contacts

TL;DR

This paper investigates the microscopic electronic structure of quantum point contacts, revealing the formation of bound states that can confine single spins, with observable Zeeman splitting under magnetic fields.

Contribution

It introduces a novel probing approach for strongly pinched-off QPCs, demonstrating self-consistent bound state formation and spin confinement.

Findings

Evidence for bound states in QPCs

Observation of Zeeman splitting of confined spins

Resonant interaction between coupled QPCs

Abstract

Using an approach that allows us to probe the electronic structure of strongly pinched-off quantum point contacts (QPCs), we provide evidence for the formation of self-consistently realized bound states (BSs) in these structures. Our approach exploits the resonant interaction between closely-coupled QPCs, and demonstrates that the BSs may give rise to a robust confinement of single spins, which show clear Zeeman splitting in a magnetic field.