Quantum information processing using localized ensembles of nuclear spins

TL;DR

This paper proposes a quantum information processing method utilizing localized nuclear spin ensembles around quantum dots, enabling long coherence times and error-resistant operations through hyperfine interactions and electron spin rotations.

Contribution

It introduces a novel scheme for quantum computing with nuclear spins that avoids entanglement-related gate errors and leverages nuclear spin coherence for long-term quantum memory.

Findings

Single and two-qubit operations are feasible with hyperfine interactions.

Nuclear spins exhibit ultra-long coherence times.

The scheme is suitable for long-lived quantum memory applications.

Abstract

We describe a technique for quantum information processing based on localized en sembles of nuclear spins. A qubit is identified as the presence or absence of a collective excitation of a mesoscopic ensemble of nuclear spins surrounding a single quantum dot. All single and two-qubit operations can be effected using hyperfine interactions and single-electron spin rotations, hence the proposed scheme avoids gate errors arising from entanglement between spin and orbital degrees of freedom. Ultra-long coherence times of nuclear spins suggest that this scheme could be particularly well suited for applications where long lived memory is essential.