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

Negatively charged boron vacancy (V_{B}^{-}) in hexagonal boron nitride is the most extensively studied room-temperature quantum spin system in two-dimensional materials. Nevertheless, the current effective readout of 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 Letter, we demonstrate a photoelectric spin readout technique for V_{B}^{-} spins in hexagonal boron nitride. The observed photocurrent signals stem from the spin-dependent ionization dynamics of boron vacancies, mediated by spin-dependent nonradiative 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 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 two-dimensional material platforms.