Flux Trapping Analysis in Superconducting Circuits

Flux trapping adversely affects the superconducting electronic circuit operation. Circuit designers would benefit from a tool to analyze the probability and effects of flux trapping at critical locations for a given circuit layout. We show how our tetrahedral volume element numerical solver, TTH, can be used to model trapped fluxons in the presence of external magnetic fields. We also show how to extract the self-inductance around holes and the mutual inductance between moats and other excitation ports. Understanding the coupling effects between moats and circuit elements such as signal lines or Josephson junctions can help determine the optimal size and placements of moats, preventing circuit performance degradation and operation malfunction.