Room-Temperature Electrical Readout of Spin Defects in van der Waals Materials

TL;DR

This paper introduces a novel photoelectric method for reading out spin states of boron vacancies in hexagonal boron nitride at room temperature, enabling compact quantum sensing and information devices.

Contribution

The study presents the first electrical detection technique for $ ext{V}_ ext{B}^-$ spins in hBN, extending quantum readout capabilities beyond optical methods.

Findings

Demonstrated photocurrent signals from spin-dependent ionization dynamics.

Enabled electrical readout of dynamical decoupling sequences like CPMG.

Achieved detection of nuclear spins via electron-nuclear double resonance.

Abstract

Negatively charged boron vacancy ($\mathrm{V_B^-}$) in hexagonal boron nitride (hBN) is the most extensively studied room-temperature quantum spin system in two-dimensional (2D) materials. Nevertheless, the current effective readout of $\mathrm{V_B^-}$ spin states is carried out by systematically optical methods. This limits their exploitation in compact and miniaturized quantum devices, which would otherwise hold substantial promise to address quantum sensing and quantum information tasks. In this study, we demonstrated a photoelectric spin readout technique for $\mathrm{V_B^-}$ spins in hBN. The observed photocurrent signals stem from the spin-dependent ionization dynamics of boron vacancies, mediated by spin-dependent non-radiative transitions to a metastable state. We further extend this electrical detection technique to enable the readout of dynamical decoupling sequences, including the Carr-Purcell-Meiboom-Gill (CPMG) protocols, and of nuclear spins via electron-nuclear double resonance. These results provide a pathway toward on-chip integration and real-field exploitation of quantum functionalities based on 2D material platforms.