Probing NV and SiV charge state dynamics using high-voltage nanosecond pulse and photoluminescence spectral analysis

TL;DR

This paper investigates how high-voltage nanosecond pulses can rapidly manipulate the charge states of NV and SiV centers in diamond, crucial for quantum technology applications, using photoluminescence spectral analysis.

Contribution

It demonstrates voltage-induced charge state conversions of NV and SiV centers with MHz transition rates, revealing the dominant SiV$^{2-}$ state and offering a new method for rapid charge state control.

Findings

High-voltage pulses cause charge state shifts in NV and SiV centers.

Transition rates of charge state conversions are approximately MHz.

Majority of SiV centers are in the doubly negatively charged state (SiV$^{2-}$).

Abstract

Nitrogen-vacancy (NV) and silicon-vacancy (SiV) color defects in diamond are promising systems for applications in quantum technology. The NV and SiV centers have multiple charge states, and their charge states have different electronic, optical and spin properties. For the NV centers, most investigations for quantum sensing applications are targeted on the negatively charged NV (NV$^{-}$), and it is important for the NV centers to be in the NV$^{-}$ state. However, it is known that the NV centers are converted to the neutrally charged state (NV$^{0}$) under laser excitation. An energetically favorable charge state for the NV and SiV centers depends on their local environments. It is essential to understand and control the charge state dynamics for their quantum applications. In this work, we discuss the charge state dynamics of NV and SiV centers under high-voltage nanosecond pulse discharges. The NV and SiV centers coexist in the diamond crystal. The high-voltage pulses enable manipulating the charge states efficiently. These voltage-induced changes in charge states are probed by their photoluminescence spectral analysis. The analysis result from the present experiment shows that the high-voltage nanosecond pulses cause shifts of the chemical potential and can convert the charge states of NV and SiV centers with the transition rates of $\sim$ MHz. This result also indicates that the major population of the SiV centers in the sample is the doubly negatively charged state (SiV$^{2-}$), which is often overlooked because of its non-fluorescent and non-magnetic nature. This demonstration paves a path for a method of rapid manipulation of the NV and SiV charge states in the future.