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Low-frequency phase locking in high-inductance superconductng nanowires



Robert Hadfield, Aaron J. Miller, Sae Woo Nam, Richard L. Kautz, Robert E. Schwall


Niobium nitride nanowires show considerable promise as high-speed single-photon detectors. We report the observation of an anomalous low-frequency ($\sim10$MHz) response in long, superconducting NbN nanowires (100nm wide, 4nm thick, and $500\mu$m long). This behavior, although strikingly reminiscent of the ac Josephson effect, can be explained by a relaxation oscillation resulting from the high inductance of the type II nanowire. All of the observed effects can be simulated using a simple resistive-hotspot/series-inductor model. The voltage pulses observed are virtually identical to the pulses induced by visible photons, and our observations give an important clue to the origin of dark counts in these detectors.
Applied Physics Letters


kinetic inductance, nanowire, niobium nitride, phase lock, photo response, relaxation oscillator, superconductor


Hadfield, R. , Miller, A. , Nam, S. , Kautz, R. and Schwall, R. (2005), Low-frequency phase locking in high-inductance superconductng nanowires, Applied Physics Letters (Accessed April 13, 2024)
Created November 7, 2005, Updated October 12, 2021