Efficient Microwave Spin Control of Negatively Charged Group-IV Color Centers in Diamond

TL;DR

This paper investigates microwave control of spin states in negatively charged group-IV color centers in diamond, revealing that specific magnetic field alignments can eliminate the need for strain in effective spin manipulation.

Contribution

It demonstrates that proper magnetic field orientation can enable strain-free microwave spin control in certain group-IV color centers, challenging previous assumptions.

Findings

Magnetic field orientation critically affects spin control efficacy.

Strain can be rendered unnecessary with specific magnetic field alignments.

Implications for improved quantum device performance.

Abstract

In this work, we provide a comprehensive overview of the microwave-induced manipulation of electronic spin states in negatively charged group-IV color centers in diamond with a particular emphasis on the influence of strain. Central to our investigation is the consideration of the full vectorial attributes of the magnetic fields involved, which are a dc field for lifting the degeneracy of the spin levels and an ac field for microwave control between two spin levels. We observe an intricate interdependence between their spatial orientations, the externally applied strain, and the resultant efficacy in spin state control. In most work to date the ac and dc magnetic field orientations have been insufficiently addressed, which has led to the conclusion that strain is indispensable for the effective microwave control of heavier group-IV vacancies, such as tin- and lead-vacancy color centers. In contrast, we find that the alignment of the dc magnetic field orthogonal to the symmetry axis and the ac field parallel to it can make the application of strain obsolete for effective spin manipulation. Furthermore, we explore the implications of this field configuration on the spin's optical initialization, readout, and gate fidelities.