Multifunctional Superconducting Nanowire Quantum Sensors

Understand

Superconducting nanowire single photon detectors (SNSPDs) offer high-quantum-efficiency and low-dark-count-rate single photon detection.

• In a growing number of cases, large magnetic fields are being incorporated into quantum microscopes, nanophotonic devices, and sensors for nuclear and high-energy physics that rely on SNSPDs, but superconducting devices generally operate poorly in large magnetic fields.
• Here, we demonstrate robust performance of amorphous SNSPDs in magnetic fields of up to $\pm 6$ T with a negligible dark count rate and unchanged quantum efficiency at typical bias currents.
• Critically, we also show that in the electrothermal oscillation regime, the SNSPD can be used as a magnetometer with sensitivity of better than 100 $\mathrm{\mu T/\sqrt{Hz}}$ and as a thermometer with sensitivity of 20 $\mathrm{\mu K/\sqrt{Hz}}$ at 1 K.