2025/03/28 by Metuh, Pietro, Paralikis, Athanasios, Wyborski, Paweł +9 · 3 citations
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Optics (physics.optics) #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2503.22670
We present superconducting nanowire single-photon detectors (SNSPDs) based on few-layer NbSe2 fully encapsulated with hexagonal boron nitride (hBN), demonstrating single-photon sensitivity. Our fabrication process preserves the superconducting properties of NbSe2 in nanowires, as confirmed by low-temperature transport measurements that show a critical temperature of Tc ≈ 6.5 K, comparable to the reported values for unpatterned sheets, and it maintains a contact resistance of ∼ 50 Ω at T = 4 K. Meandered NbSe2 nanowires exhibit a responsivity of up to 4.9 × 104 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 1/e recovery time of τ= (135 ± 36) ns, system timing jitter of jsys = (1103 ± 7) ps, and detection efficiency of ∼ 0.01% at 0.95Ic, 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 33% in detecting individual optical pulses, establishing the platform as a promising candidate for developing efficient single-photon detectors.