Observation of Hysteretic Transport Due to Dynamic Nuclear Spin Polarization in a GaAs Lateral Double Quantum Dot

TL;DR

This paper reports a novel hysteretic transport phenomenon in a GaAs double quantum dot caused by dynamic nuclear spin polarization, revealing potential for controlling spin states through DC transport in quantum devices.

Contribution

It demonstrates a new hysteretic transport feature linked to DNP in GaAs quantum dots, highlighting the role of inter-dot coupling and spin level crossings.

Findings

Hysteresis appears only during magnetic field sweeps.

Large DNP signals suggest unbalanced nuclear polarization.

Potential for spin control via DC transport.

Abstract

We report a new transport feature in a GaAs lateral double quantum dot that emerges only for magnetic field sweeps and shows hysteresis due to dynamic nuclear spin polarization (DNP). This DNP signal appears in the Coulomb blockade regime by virtue of the finite inter-dot tunnel coupling and originates from the crossing between ground levels of the spin triplet and singlet extensively used for nuclear spin manipulations in pulsed gate experiments. The unexpectedly large signal intensity is suggestive of unbalanced DNP between the two dots, which opens up the possibility of controlling electron and nuclear spin states via DC transport.