Nuclear spin coherence in a quantum wire

TL;DR

This study demonstrates millisecond-long nuclear spin coherence in a quantum wire at low temperature, achieved through electrical manipulation and dynamic nuclear polarization, with potential applications in quantum information processing.

Contribution

It introduces a novel method for local electrical control of nuclear spins in a quantum wire, enabling long coherence times and qubit-like behavior.

Findings

Nuclear spins exhibit millisecond coherence times.

Electrical manipulation of nuclear spins is achieved via dynamic nuclear polarization.

The system functions as a two-qubit four-level spin system.

Abstract

We have observed millisecond-long coherent evolution of nuclear spins in a quantum wire at 1.2 K. Local, all-electrical manipulation of nuclear spins is achieved by dynamic nuclear polarization in the breakdown regime of the Integer Quantum Hall Effect combined with pulsed Nuclear Magnetic Resonance. The excitation thresholds for the breakdown are significantly smaller than what would be expected for our sample and the direction of the nuclear polarization can be controlled by the voltage bias. As a four-level spin system, the device is equivalent to two qubits.