Two-fluid physical modeling of superconducting resonators in the ARTEMIS framework*

In this work, we implement a new London equation module for superconductivity in the GPU-enabled ARTEMIS framework, and couple it to a finite-difference time-domain solver for Maxwell's equations. We apply this two-fluid approach to model a superconducting coplanar waveguide (CPW) resonator. We validate our implementation by verifying that the theoretical skin depth and reflection coefficients can be obtained for several superconductive materials, with different London penetration depths, over a range of frequencies. Our convergence studies show that the algorithm is second-order accurate in both space and time, except at superconducting interfaces where the approach is spatially first-order. In our CPW simulations, we leverage the GPU scalability of our code to compare the two-fluid model to more traditional approaches that approximate superconducting behavior and demonstrate that superconducting physics can show comparable performance to the assumption of quasi-infinite conductivity as measured by the Q-factor.& COPY; 2023 Published by Elsevier B.V.

Automated summary

In this study, a new London equation module for superconductivity is implemented in the GPU-enabled ARTEMIS framework and coupled with a finite-difference time-domain solver for Maxwell's equations. The two-fluid approach is applied to model a superconducting coplanar waveguide (CPW) resonator. The implementation is validated by obtaining the theoretical skin depth and reflection coefficients for various superconductive materials with different London penetration depths at different frequencies. The convergence studies show that the algorithm is second-order accurate in both space and time, except at superconducting interfaces where it is first-order accurate in space. In CPW simulations, the two-fluid model is compared to traditional approaches approximating superconducting behavior, demonstrating comparable performance to the assumption of quasi-infinite conductivity as measured by the Q-factor.