Zero field optical magnetic resonance study of phosphorus donors in 28-silicon

TL;DR

This study explores phosphorus donor spins in silicon at zero magnetic field, demonstrating optical hyperpolarization and long coherence times, advancing solid-state quantum bit research.

Contribution

It introduces a zero-field optical magnetic resonance technique for phosphorus donors in silicon, revealing long coherence times and hyperpolarization capabilities.

Findings

Achieved ~10 s Hahn echo coherence times at Earth's magnetic field.

Demonstrated optical hyperpolarization of phosphorus donor spins.

Characterized zero-field spin transitions using laser spectroscopy.

Abstract

Donor spins in silicon are some of the most promising qubits for upcoming solid-state quantum technologies. The nuclear spins of phosphorus donors in enriched silicon have among the longest coherence times of any solid-state system as well as simultaneous qubit initialization, manipulation and readout fidelities near ~99.9%. Here we characterize the phosphorus in silicon system in the regime of "zero" magnetic field, where a singlet-triplet spin clock transition can be accessed, using laser spectroscopy and magnetic resonance methods. We show the system can be optically hyperpolarized and has ~10 s Hahn echo coherence times, even at Earth's magnetic field and below.