Description
Electrical detection of solid-state spins is attractive for quantum technologies, being readily chip-scalable while avoiding the small photon budgets of single emitters. Photoelectrically-detected magnetic resonance (PDMR) provides one such route [1], but carrier trapping by bulk impurities limits photocurrent, throttles bandwidth, and introduces charge transfer dynamics that complicate readout [2].
Here, we read the spin state of single nitrogen-vacancy (NV) centres in diamond by storing spin-dependent photocarrier emissions in room-temperature interface traps at a diamond–metal junction [Ulibarri et al., arXiv:2510.25619 (2025)]. These trapped charges remain stable for at least 24 hours and are read out on demand by illuminating the electrically-biased interface — not the spin qubit itself — generating a current transient enhanced by photoconductive gain and proportional to the NV spin state. NV-sourced photocarriers are captured by long-lived trap states at the Schottky barrier [3], storing spin information in a manner analogous to bulk charge trapping observed in NV ensembles [4].
On this basis we introduce charge-capture detected magnetic resonance (CCDMR), a new spin-state detection scheme. CCDMR circumvents key PDMR shortcomings bandwidth limitations of high-sensitivity current amplifiers, and microwave-induced crosstalk. For a single NV centre, we observe a resonance at 2.87 GHz with ~11% contrast. We further demonstrate the full suite of quantum measurement tools including Rabi oscillations and Hahn-echo, with increased spin to charge conversion fidelity achieved via pulsed excitation. We verify the species of trapped charges through dynamic imaging of carrier transport and trapping.
These results establish CCDMR as a new technique for solid-state spin qubit readout, representing a step toward room-temperature, all-electrical quantum sensing schemes.
[1] Bourgeois et al., Nat. Commun. 6, 8577 (2015)
[2] Wood et al., Adv. Mater. 36(40):e2405338 (2024)
[3] Sze & Ng, Physics of Semiconductor Devices, ISBN: 9780471143239
[4] Jayakumar et al., Phys. Rev. Lett. 125, 236601 (2020)
| I am the presenting author | Yes |
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