Fig. 1: Single Josephson junction resonator.
From: High-impedance microwave resonators with two-photon nonlinear effects
a A scanning electron micrograph of the measured resonator device. The resonance mode forms across a Josephson junction connecting the bottom ground plane (dark grey) to the resonator middle line (colored in teal). The resonator is driven and measured via an input and output lines colored in blue. b A zoom-in to the junction area. The single junction is split into two junctions highlighted with dashed teal rectangles to form a SQUID geometry for tuning the resonance frequency. c The effective electric circuit for the first photon. d The resonator transmission coefficient T as a function of magnetic flux Φ and drive frequency f. At frequency f = 4.7 GHz the input power is P = 8.6 aW (see the Methods section for details). e Transmission T and reflection coefficient R measured at Φ = 0.4Φ0. The solid lines are fits to Eq. (1) of ref. 28 with f01 = 4.86 GHz, κc/2π = 12 MHz and κi/2π = 3 MHz.
