Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1904.08596 · Physical review. B./Physical review. B

Determining the depairing current in superconducting nanowire single-photon detectors

Simone Frasca, Boris A. Korzh, Marco Colangelo, Di Zhu, Adriana E. Lita, Jason P. Allmaras, Emma E. Wollman, Varun Boehm Verma, Andrew E. Dane, Edward Ramirez, Andrew D. Beyer, Sae Woo Nam, Alexander G. Kozorezov, Matthew D. Shaw, Karl K. Berggren

Published Aug 30, 2019• 50 citations
arXivHTMLPDF

Abstract

This work presents a method to estimate experimentally the superconducting depairing current of ultrathin films by means of nanowire-style resonators. Measuring the depairing current allows for a better determination of the figure of merit for the quality of superconducting nanowires. The resonance is set by impedance mismatch between the nanowire and the transmission line. Bias current dependent shifts in the measured resonant frequency correspond to the change in the kinetic inductance, which can be compared with theoretical predictions to estimate the resonator superconducting depairing current. The experiments lead to an unexpected and original result - a decrease of the switching-to-depairing current ratio with increasing temperature.

DOI
10.1103/physrevb.100.054520

Related papers

Understanding multiscale disorder in superconducting nanowire single photon detectors

Nirjhar Sarkar, Ronan Gourgues, Yueh-Chun Wu +7 more

Superconducting nanowire single-photon detectors are central to applications across quantum information science. Yet, their performance is limited by the effects of disorder and electrodynamic inhomogeneities that are not well understood. By combining DC transport, dark-count measurements, and bias-dependent microwave transmission spectroscopy in the presence of controlled nanoscale disorder introduced through helium-ion irradiation, we distinguish local instability-driven processes from intrinsic superconducting depairing and kinetic inductance nonlinearities. This approach enables systematic tuning of kinetic inductance, depairing currents, microwave dissipation, and mode structure within a single device. Bias- and temperature-dependent resonance shifts quantify disorder-induced modifications of the superconducting density of states through the nonlinear kinetic inductance, while the emergence of multiple resonant modes reveals the formation of electrodynamically distinct superconducting regions. Comparing depairing under current, field, and temperature isolates the dominant microwave loss mechanisms, separating vortex, quasiparticle, and two-level-system contributions, thus providing a robust multifunctional foundation for disorder engineering of superconducting nanowire detectors and resonators.

quant-pharXiv:2601.23277•Feb 2, 2026•0 citations

Effect of temperature oscillations on kinetic inductance and depairing in thin and narrow superconducting nanowire resonators

Jason P. Allmaras, Alexander G. Kozorezov, Marco Colangelo +3 more

Recent experiments have demonstrated a method for extracting the depairing current of nanowires fabricated from thin-film dirty superconductors using the AC response of DC-current biased resonators. While the existing theoretical model for understanding this response, developed by Clem and Kogan, provides agreement with Eilenberger-Usadel theory at low temperatures, there is a systematic and substantial deviation from theory at elevated temperatures. We propose that the DC bias in the presence of electromagnetic oscillations leads to Joule heating in the superconductor. This heating, combined with the strong electron-electron scattering in these heavily disordered materials, leads to oscillations in the effective temperature of the superconductor which alter the kinetic inductance. In this work, we derive the expression for the shift in kinetic inductance in the presence of a bias current and demonstrate that this model provides a significantly improved agreement between experiment and theory.

Physical review. B./Physical review. B•Mar 30, 2023•2 citations

Demonstration of Microwave Multiplexed Readout of DC-Biased Superconducting Nanowire Detectors

Sinclair, AK, Schroeder, E, Di Zhu +5 more

© 2002-2011 IEEE. Superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. We describe a demonstration of an array of dc-biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. In this design, each individual nanowire is part of a resonant LC circuit where the inductance is dominated by the kinetic inductance of the nanowire. The circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line that carries the signals to a cryogenic low-noise amplifier. All of the nanowires are connected via resistors to a single dc bias line that enables the nanowires to be current biased close to their critical current. When a photon hits a nanowire, it creates a normal hotspot that produces a voltage pulse across the LC circuit. This pulse rings down at the resonant frequency of the LC circuit over a time period that is fixed by the quality factor. We present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.

•Jan 1, 2019•14 citations

Demonstration of Microwave Multiplexed Readout of DC-Biased Superconducting Nanowire Detectors

A. K. Sinclair, E. Schroeder, Di Zhu +5 more

Superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. We describe a demonstration of an array of dc-biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. In this design, each individual nanowire is part of a resonant LC circuit where the inductance is dominated by the kinetic inductance of the nanowire. The circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line that carries the signals to a cryogenic low-noise amplifier. All of the nanowires are connected via resistors to a single dc bias line that enables the nanowires to be current biased close to their critical current. When a photon hits a nanowire, it creates a normal hotspot that produces a voltage pulse across the LC circuit. This pulse rings down at the resonant frequency of the LC circuit over a time period that is fixed by the quality factor. We present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.

arXiv:1905.06880•IEEE Transactions on Applied Superconductivity•Mar 8, 2019•26 citations

Microwave dynamics of high aspect ratio superconducting nanowires studied using self-resonance

Daniel F. Santavicca, Jesse K. Adams, Lierd E. Grant +2 more

We study the microwave impedance of extremely high aspect ratio (length/width ≈ 5000) superconducting niobium nitride nanowires. The nanowires are fabricated in a compact meander geometry that is in series with the center conductor of a 50 Ω coplanar waveguide transmission line. The transmission coefficient of the sample is measured up to 20 GHz. At high frequency, a peak in the transmission coefficient is seen. Numerical simulations show that this is a half-wave resonance along the length of the nanowire, where the nanowire acts as a high impedance, slow wave transmission line. This resonance sets the upper frequency limit for these nanowires as inductive elements. Fitting simulations to the measured resonance enables a precise determination of the nanowire's complex sheet impedance at the resonance frequency. The real part is a measure of dissipation, while the imaginary part is dominated by kinetic inductance. We characterize the dependence of the sheet resistance and sheet inductance on both temperature and current and compare the results to recent theoretical predictions for disordered superconductors. These results can aid in the understanding of high frequency devices based on superconducting nanowires. They may also lead to the development of novel superconducting devices such as ultra-compact resonators and slow-wave structures.

arXiv:1602.06895•Journal of Applied Physics•Jun 15, 2016•46 citations

Microwave dynamics of high aspect ratio superconducting nanowires studied using self-resonance

Daniel F. Santavicca, Adams, Jesse K., Grant, Lierd E. +2 more

We study the microwave impedance of extremely high aspect ratio (length/width ≈ 5000) superconducting niobium nitride nanowires. The nanowires are fabricated in a compact meander geometry that is in series with the center conductor of a 50 Ω coplanar waveguide transmission line. The transmission coefficient of the sample is measured up to 20 GHz. At high frequency, a peak in the transmission coefficient is seen. Numerical simulations show that this is a half-wave resonance along the length of the nanowire, where the nanowire acts as a high impedance, slow wave transmission line. This resonance sets the upper frequency limit for these nanowires as inductive elements. Fitting simulations to the measured resonance enables a precise determination of the nanowire's complex sheet impedance at the resonance frequency. The real part is a measure of dissipation, while the imaginary part is dominated by kinetic inductance. We characterize the dependence of the sheet resistance and sheet inductance on both temperature and current and compare the results to recent theoretical predictions for disordered superconductors. These results can aid in the understanding of high frequency devices based on superconducting nanowires. They may also lead to the development of novel superconducting devices such as ultra-compact resonators and slow-wave structures.

•Jun 1, 2016•31 citations
This work presents a method to estimate experimentally the superconducting depairing current of ultrathin films by means of nanowire-style resonators. Measuring the depairing current allows for a better determination of the figure of merit for the quality of superconducting nanowires. The resonance is set by impedance mismatch between the nanowire and the transmission line. Bias current dependent shifts in the measured resonant frequency correspond to the change in the kinetic inductance, which can be compared with theoretical predictions to estimate the resonator superconducting depairing current. The experiments lead to an unexpected and original result - a decrease of the switching-to-depairing current ratio with increasing temperature.
Superconducting nanowire single-photon detectors are central to applications across quantum information science. Yet, their performance is limited by the effects of disorder and electrodynamic inhomogeneities that are not well understood. By combining DC transport, dark-count measurements, and bias-dependent microwave transmission spectroscopy in the presence of controlled nanoscale disorder introduced through helium-ion irradiation, we distinguish local instability-driven processes from intrinsic superconducting depairing and kinetic inductance nonlinearities. This approach enables systematic tuning of kinetic inductance, depairing currents, microwave dissipation, and mode structure within a single device. Bias- and temperature-dependent resonance shifts quantify disorder-induced modifications of the superconducting density of states through the nonlinear kinetic inductance, while the emergence of multiple resonant modes reveals the formation of electrodynamically distinct superconducting regions. Comparing depairing under current, field, and temperature isolates the dominant microwave loss mechanisms, separating vortex, quasiparticle, and two-level-system contributions, thus providing a robust multifunctional foundation for disorder engineering of superconducting nanowire detectors and resonators.
Recent experiments have demonstrated a method for extracting the depairing current of nanowires fabricated from thin-film dirty superconductors using the AC response of DC-current biased resonators. While the existing theoretical model for understanding this response, developed by Clem and Kogan, provides agreement with Eilenberger-Usadel theory at low temperatures, there is a systematic and substantial deviation from theory at elevated temperatures. We propose that the DC bias in the presence of electromagnetic oscillations leads to Joule heating in the superconductor. This heating, combined with the strong electron-electron scattering in these heavily disordered materials, leads to oscillations in the effective temperature of the superconductor which alter the kinetic inductance. In this work, we derive the expression for the shift in kinetic inductance in the presence of a bias current and demonstrate that this model provides a significantly improved agreement between experiment and theory.
© 2002-2011 IEEE. Superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. We describe a demonstration of an array of dc-biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. In this design, each individual nanowire is part of a resonant LC circuit where the inductance is dominated by the kinetic inductance of the nanowire. The circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line that carries the signals to a cryogenic low-noise amplifier. All of the nanowires are connected via resistors to a single dc bias line that enables the nanowires to be current biased close to their critical current. When a photon hits a nanowire, it creates a normal hotspot that produces a voltage pulse across the LC circuit. This pulse rings down at the resonant frequency of the LC circuit over a time period that is fixed by the quality factor. We present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.
Superconducting nanowires are widely used as sensitive single photon detectors with wide spectral coverage and high timing resolution. We describe a demonstration of an array of dc-biased superconducting nanowire single photon detectors read out with a microwave multiplexing circuit. In this design, each individual nanowire is part of a resonant LC circuit where the inductance is dominated by the kinetic inductance of the nanowire. The circuit also contains two parallel plate capacitors, one of them is in parallel with the inductor and the other is coupled to a microwave transmission line that carries the signals to a cryogenic low-noise amplifier. All of the nanowires are connected via resistors to a single dc bias line that enables the nanowires to be current biased close to their critical current. When a photon hits a nanowire, it creates a normal hotspot that produces a voltage pulse across the LC circuit. This pulse rings down at the resonant frequency of the LC circuit over a time period that is fixed by the quality factor. We present measurements of an array of these devices and an evaluation of their performance in terms of frequency and time response.
We study the microwave impedance of extremely high aspect ratio (length/width ≈ 5000) superconducting niobium nitride nanowires. The nanowires are fabricated in a compact meander geometry that is in series with the center conductor of a 50 Ω coplanar waveguide transmission line. The transmission coefficient of the sample is measured up to 20 GHz. At high frequency, a peak in the transmission coefficient is seen. Numerical simulations show that this is a half-wave resonance along the length of the nanowire, where the nanowire acts as a high impedance, slow wave transmission line. This resonance sets the upper frequency limit for these nanowires as inductive elements. Fitting simulations to the measured resonance enables a precise determination of the nanowire's complex sheet impedance at the resonance frequency. The real part is a measure of dissipation, while the imaginary part is dominated by kinetic inductance. We characterize the dependence of the sheet resistance and sheet inductance on both temperature and current and compare the results to recent theoretical predictions for disordered superconductors. These results can aid in the understanding of high frequency devices based on superconducting nanowires. They may also lead to the development of novel superconducting devices such as ultra-compact resonators and slow-wave structures.
We study the microwave impedance of extremely high aspect ratio (length/width ≈ 5000) superconducting niobium nitride nanowires. The nanowires are fabricated in a compact meander geometry that is in series with the center conductor of a 50 Ω coplanar waveguide transmission line. The transmission coefficient of the sample is measured up to 20 GHz. At high frequency, a peak in the transmission coefficient is seen. Numerical simulations show that this is a half-wave resonance along the length of the nanowire, where the nanowire acts as a high impedance, slow wave transmission line. This resonance sets the upper frequency limit for these nanowires as inductive elements. Fitting simulations to the measured resonance enables a precise determination of the nanowire's complex sheet impedance at the resonance frequency. The real part is a measure of dissipation, while the imaginary part is dominated by kinetic inductance. We characterize the dependence of the sheet resistance and sheet inductance on both temperature and current and compare the results to recent theoretical predictions for disordered superconductors. These results can aid in the understanding of high frequency devices based on superconducting nanowires. They may also lead to the development of novel superconducting devices such as ultra-compact resonators and slow-wave structures.