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

Microwave and Optical Technology Letters

Measurement of the current‐density distribution in high‐temperature superconducting microstrip by means of kinetic‐inductance photoresponse (invited paper)

Harvey S. Newman, James C. Culbertson

Published Oct 1, 1993• 13 citations
Publisher

Abstract

Abstract We report a technique for measuring the spatial profile of microwave‐frequency currents in resonant thin‐film superconducting microstrip devices operated near resonance. We probe the patterned superconducting device as a function of position by scanning a modulated light beam across the region to be probed. With the light focused to a spot size much smaller than the microstrip width, we have measured the current density distribution as a function of position across the width of the strip. Using an elementary model for the superconducting current density distribution, we fit an effective penetration depth at the edge of the microstrip. © 1993 John Wiley & Sons, Inc.

DOI
10.1002/mop.4650061303

Related papers

Imaging local sources of intermodulation in superconducting microwave devices

Alexander P. Zhuravel, Alexey Vladimirovich Ustinov, D. Abraimov +1 more

This work presents new experimental results on low-temperature (LT) characterization of local RF properties of passive superconducting (SC) microwave devices using a novel laser scanning microscope (LSM). In this technique, a modulated laser beam is focused onto and scanned over the surface of a resonant SC device to probe the spatial distribution of RF current. The highly localized photo-induced change of the kinetic inductance of the SC device produces both a shift of the resonant frequency f/sub 0/ and change of the quality factor Q. An image of these changes is recorded as the laser spot is scanned over the device. We present the first measurements of spatially resolved intermodulation response in a high temperature superconducting (HTS) co-planar waveguide resonator, opening up a new window into the local origins of nonlinearity in the HTS materials.

arXiv:cond-mat/0211191•IEEE Transactions on Applied Superconductivity•Jun 1, 2003•22 citations

Absolute measurement of penetration depth of superconducting thin films using microwave stripline resonators

Arghya Dutta, Ajeet Salunke, Mahesh Poojary +3 more

Superconducting microstrip resonators, which leverage kinetic inductance to probe electrodynamics, are sensitive tools for studying superconducting thin films at microwave frequencies. However, extracting the absolute superconducting penetration depth from these measurements remains challenging. In this work, we present a hybrid method to determine the absolute value of penetration depth over a wide temperature range by combining resonator measurements with finite-element electromagnetic simulations in COMSOL Multiphysics. We demonstrate this approach by extracting the penetration depth of NbN films by fabricating resonators from films of various thicknesses. Furthermore, we extend the technique to materials with lower critical temperatures by employing a flip-film geometry. By placing a sample above a NbN resonator, separated by a thin Mylar dielectric, we create a coupled structure where changes in the sample's penetration depth shift the resonant frequency. This non-destructive method provides a reliable, high-sensitivity platform for characterizing the penetration depth of diverse superconducting thin films.

arXiv:2605.28759•May 27, 2026•0 citations

The discovery of a technique to measure the spatial profile of microwave frequency superconducting current densities

Jim C. Culbertson

We have discovered that the optically induced shift in the resonance frequency of a resonant superconducting device is proportional to the square of the local superconducting current density. Using rapidly modulated, highly focused light sources, such measurements, performed as a function of position, can be useful in the study and design of superconducting devices.

International Conference on Millimeter and Submillimeter Waves and Applications 1994•Jan 1, 1994•1 citation

Influence of LaAlO3 surface topography on rf current distribution in superconducting microwave devices

Alexander P. Zhuravel, Alexey Vladimirovich Ustinov, K. Solomon Harshavardhan +1 more

A laser scanning microscope with a thermal spot size of about 4 μm is used to measure a quantity proportional to the rf current density in an operating superconducting coplanar waveguide microwave resonator. The twinning of the LaAlO3 substrate produces a meandering of the current at the edges due to irregularities in the wet etching of the YBa2Cu3O7−δ film associated with substrate twin domain blocks, and an (∼20%) enhancement of the rf photoresponse at these locations. These irregularities are candidates for enhanced nonlinear response from the device.

arXiv:cond-mat/0209614•Applied Physics Letters•Dec 19, 2002•33 citations

Microwave nonlinearity and photoresponse of superconducting resonators with columnar defect micro-channels

Stephen K. Remillard, D Kirkendall, G. Ghigo +9 more

Micro-channels of nanosized columnar tracks were planted by heavy-ion irradiation into superconducting microwave microstrip resonators that were patterned from YBa2Cu3O7-x thin films on LaAlO3 substrates. Three different ion fluences were used, producing different column densities, with each fluence having a successively greater impact on the nonlinearity of the device, as compared to a control sample. Photoresponse images made with a 638 nm rastered laser beam revealed that the channel is a location of enhanced photoresponse and a hot spot for the generation of intermodulation distortion. The microwave photoresponse technique was also advanced in this work by investigating the role of coupling strength on the distribution of photoresponse between inductive and resistive components.

arXiv:1403.6914•Superconductor Science and Technology•Aug 12, 2014•11 citations

Impact of kinetic inductance effect on high‐Tc

A.Z. Kain, J.M. Pond, Harold R. Fetterman +1 more

Abstract High‐Q transmission high‐Tcsuperconducting coplanar waveguide resonators have been employed to make accurate measurements of the temperature dependence of the penetration depth via the change in phase velocity. Resonators made from several different film thicknesses are well described using a zero temperature penetration depth and a T‐squared temperature dependence using a full‐wave spectral‐domain model of the coplanar waveguide transmission line. © 1993 John Wiley & Sons, Inc.

Microwave and Optical Technology Letters•Oct 1, 1993•9 citations
Abstract We report a technique for measuring the spatial profile of microwave‐frequency currents in resonant thin‐film superconducting microstrip devices operated near resonance. We probe the patterned superconducting device as a function of position by scanning a modulated light beam across the region to be probed. With the light focused to a spot size much smaller than the microstrip width, we have measured the current density distribution as a function of position across the width of the strip. Using an elementary model for the superconducting current density distribution, we fit an effective penetration depth at the edge of the microstrip. © 1993 John Wiley & Sons, Inc.
This work presents new experimental results on low-temperature (LT) characterization of local RF properties of passive superconducting (SC) microwave devices using a novel laser scanning microscope (LSM). In this technique, a modulated laser beam is focused onto and scanned over the surface of a resonant SC device to probe the spatial distribution of RF current. The highly localized photo-induced change of the kinetic inductance of the SC device produces both a shift of the resonant frequency f/sub 0/ and change of the quality factor Q. An image of these changes is recorded as the laser spot is scanned over the device. We present the first measurements of spatially resolved intermodulation response in a high temperature superconducting (HTS) co-planar waveguide resonator, opening up a new window into the local origins of nonlinearity in the HTS materials.
Superconducting microstrip resonators, which leverage kinetic inductance to probe electrodynamics, are sensitive tools for studying superconducting thin films at microwave frequencies. However, extracting the absolute superconducting penetration depth from these measurements remains challenging. In this work, we present a hybrid method to determine the absolute value of penetration depth over a wide temperature range by combining resonator measurements with finite-element electromagnetic simulations in COMSOL Multiphysics. We demonstrate this approach by extracting the penetration depth of NbN films by fabricating resonators from films of various thicknesses. Furthermore, we extend the technique to materials with lower critical temperatures by employing a flip-film geometry. By placing a sample above a NbN resonator, separated by a thin Mylar dielectric, we create a coupled structure where changes in the sample's penetration depth shift the resonant frequency. This non-destructive method provides a reliable, high-sensitivity platform for characterizing the penetration depth of diverse superconducting thin films.
A laser scanning microscope with a thermal spot size of about 4 μm is used to measure a quantity proportional to the rf current density in an operating superconducting coplanar waveguide microwave resonator. The twinning of the LaAlO3 substrate produces a meandering of the current at the edges due to irregularities in the wet etching of the YBa2Cu3O7−δ film associated with substrate twin domain blocks, and an (∼20%) enhancement of the rf photoresponse at these locations. These irregularities are candidates for enhanced nonlinear response from the device.
Micro-channels of nanosized columnar tracks were planted by heavy-ion irradiation into superconducting microwave microstrip resonators that were patterned from YBa2Cu3O7-x thin films on LaAlO3 substrates. Three different ion fluences were used, producing different column densities, with each fluence having a successively greater impact on the nonlinearity of the device, as compared to a control sample. Photoresponse images made with a 638 nm rastered laser beam revealed that the channel is a location of enhanced photoresponse and a hot spot for the generation of intermodulation distortion. The microwave photoresponse technique was also advanced in this work by investigating the role of coupling strength on the distribution of photoresponse between inductive and resistive components.
Abstract High‐Q transmission high‐Tcsuperconducting coplanar waveguide resonators have been employed to make accurate measurements of the temperature dependence of the penetration depth via the change in phase velocity. Resonators made from several different film thicknesses are well described using a zero temperature penetration depth and a T‐squared temperature dependence using a full‐wave spectral‐domain model of the coplanar waveguide transmission line. © 1993 John Wiley & Sons, Inc.