Multi-photon multi-quantum transitions in the spin-3/2 silicon-vacancy centers of SiC

TL;DR

This paper investigates multi-photon quantum transitions in silicon vacancy centers in SiC, revealing nonlinear effects and Rabi oscillations at low magnetic fields, advancing understanding of quantum control in these systems.

Contribution

It demonstrates the first observation of time-resolved Rabi oscillations and free induction decays for multi-photon transitions in silicon vacancy centers in SiC.

Findings

Identification of 1-, 2-, and 3-photon transitions in ODMR spectra.

First observation of Rabi oscillations for multi-photon transitions.

Spectra obtained under various magnetic field conditions.

Abstract

Silicon vacancy centers in silicon carbide are promising candidates for storing and manipulating quantum information. Implementation of fast quantum gates is an essential requirement for quantum information processing. In a low magnetic field, the resonance frequencies of silicon vacancy spins are in the range of a few MHz, the same order of magnitude as the Rabi frequencies of typical control fields. As a consequence, the rotating wave approximation becomes invalid and nonlinear processes like the absorption and emission of multiple photons become relevant. This work focuses on multi-photon transitions of negatively charged silicon vacancies driven by a strong RF field. We present continuous-wave optically detected magnetic resonance (ODMR) spectra measured at different RF powers to identify the 1-, 2-, and 3-RF photon transitions of different types of the silicon vacancy in the 6$H$-SIC polytype. Time-resolved experiments of Rabi oscillations and free induction decays of these multiple RF photon transitions were observed for the first time. Apart from zero-field data, we also present spectra in magnetic fields with different strength and orientation with respect to the system's symmetry axis.