Toward single-photon detection with superconducting niobium diselenide nanowires
arXiv:2503.22670 · doi:10.1021/acsphotonics.5c01195
Abstract
We present superconducting nanowire single-photon detectors (SNSPDs) based on few-layer NbSe fully encapsulated with hexagonal boron nitride (hBN), demonstrating single-photon sensitivity. Our fabrication process preserves the superconducting properties of NbSe in nanowires, as confirmed by low-temperature transport measurements that show a critical temperature of K, comparable to the reported values for unpatterned sheets, and it maintains a contact resistance of at K. Meandered NbSe nanowires exhibit a responsivity of up to V/W over a spectral range of 650-1550 nm in a closed-cycle cryostat at 4 K, outperforming planar and short-wire devices. The devices achieve a recovery time of ns, system timing jitter of ps, and detection efficiency of at , with a linear increase in detection probability confirming the single-photon operation. Furthermore, measurements under attenuated pulsed laser (1 MHz) indicate a success rate of up to in detecting individual optical pulses, establishing the platform as a promising candidate for developing efficient single-photon detectors.