DC Flux Dependance of Intermodulation Products in Nonlinear RF-SQUID Metamaterials

Radio Frequency (RF) Superconducting Quantum Interference Device (SQUID) metamaterials have demonstrated strong intrinsic nonlinearity [PRB 94, 174507 (2016)] as well as complex collective behavior [PRE 95, 050201 (2017); APL 114, 082601 (2019)]. In the case of multi-frequency excitation, intermodulation (IM) products can be strongly enhanced, or suppressed, by tuning frequency and RF flux amplitude. However, the DC flux dependence of these IM products has yet to be explored. This presentation will compare experimental data of the DC flux dependence to several numerical and analytic models of the rf-SQUID. Further, these models explain multi-stable transitions near the geometric resonance and predict the existence of chaotic behavior in a single rf-SQUID [Chaos 28, 063117 (2018)]. These features should be visible to future experiments and could potentially lead to the discovery of new and useful behaviors in rf-SQUID metamaterials.