Two Dimensional Wireless Josephson Junction Arrays: A Microwave Transmission Investigation

We investigate the flow of Cooper pairs and unpaired electrons though an unbiased ordered 2D lattice of superconductor-insulator-superconductor tunnel junctions in the presence of an AC microwave field. The transmission reveals a robust resonance at temperatures below the transition temperature,T$_c$, and at low microwave power. As power is increased at fixed temperature, below T$_c$, resonant peaks split into two. In aggregate, these split peaks show well defined frequency steps for a range of temperatures. We review this data from various viewpoints, including the Berezinskii-Kosterlitz-Thouless phase transition, Shapiro steps, and as an 'artificial' supersolid. We gratefully acknowledge Professors Steven Anlage and Allen Goldman’s support.