Voltage-Tuned Dissipation in Frustrated Hybrid Josephson Junction Arrays

We report transport measurements on dice-lattice Josephson junction arrays defined by narrow superconducting Al islands, surrounded by plaquettes of normal conducting InAs. Applying a flux-threading external magnetic field and current bias we observe an intricate magnetic frustration pattern with a series of commensurate and incommensurate states. Here, we focus on the geometry-independent integer-frustrations using a global top-gate to tune the population of the normal conducting plaquettes. For populated plaquettes, we observe the envelope of integer-frustration peaks to be strongly dependent on magnetic field, exhibiting thin-film-like behavior. When plaquettes are depleted, the envelope shows only a weak dependence on external magnetic field, behaving as a network of nanowires. We interpret our observations in the context of dissipation due to the inverse proximity effect, which is suppressed as the 2DEG is depleted.