Theory of NMR in semiconductor quantum point contact devices

TL;DR

This paper explores how nuclear magnetic resonance techniques can be applied to semiconductor quantum point contacts to understand electron interactions, especially related to the 0.7 conductance anomaly, through electrical detection of nuclear polarization.

Contribution

It introduces a method to generate and detect local nuclear polarization electrically in quantum point contacts, linking nuclear spin relaxation to electron interaction mechanisms.

Findings

Nuclear polarization can be electrically generated and detected.

Nuclear spin relaxation rates reveal interaction mechanisms.

NMR methods can be adapted for nanoscale electronic devices.

Abstract

We describe how a local non-equilibrium nuclear polarisation can be generated and detected by electrical means in a semiconductor quantum point contact device. We show that measurements of the nuclear spin relaxation rate will provide clear signatures of the interaction mechanism underlying the "0.7" conductance anomaly. Our analysis illustrates how nuclear magnetic resonance methods, which are used extensively to study strongly-correlated electron phases in bulk materials, can be made to play a similarly important role in nanoscale devices.