Spin dependent recombination based magnetic resonance spectroscopy of bismuth donor spins in silicon at low magnetic fields

TL;DR

This study demonstrates low-field magnetic resonance spectroscopy of bismuth donor spins in silicon, revealing unique spin-dependent recombination signals and tunable excitation energy suitable for quantum computing applications.

Contribution

It introduces a novel low-field magnetic resonance technique for Bi donors in silicon based on spin-dependent recombination, with insights into recombination mechanisms and energy tunability.

Findings

Distinct signal distributions at low magnetic fields

Recombination rates vary with spin state combinations

Bi excitation energy is highly tunable at low fields

Abstract

Low-field (6-110 mT) magnetic resonance of bismuth (Bi) donors in silicon has been observed by monitoring the change in photoconductivity induced by spin dependent recombination. The spectra at various resonance frequencies show signal intensity distributions drastically different from that observed in conventional electron paramagnetic resonance, attributed to different recombination rates for the forty possible combinations of spin states of a pair of a Bi donor and a paramagnetic recombination center. An excellent tunability of Bi excitation energy for the future coupling with superconducting flux qubits at low fields has been demonstrated.