Abstract

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.

Abstract

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.

Abstract

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.

Abstract

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.