Figure 1
Sample structure. (a) Optical top image of the measured sample. (b) False-colour scanning electron microscope image of the coupling capacitor between the two resonators, and (c) between Resonator 1 (light blue) and the port to the external transmission line (dark blue). (d) Two micrographs of the SQUID loop highlighted in blue and the junctions highlighted in red. (e) Two micrographs of the termination Cu resistor (red). (f) Electrical circuit diagram of the sample. Resonators 1 and 2 with characteristic impedances Z0 are coupled to each other by a coupling capacitance CT and to external transmission lines with characteristic impedance ZL by capacitances CC. The inductance of the SQUID is denoted by L, and the termination resistance by R. The SQUID is connected to the centre conductor of Resonator 2 line with capacitances CL, and the resistor to centre conductor and ground with CR1 and CR2, respectively. The lengths of the resonator sections are denoted by x1/2. The image in panel (a) is from Sample A, and those in panels (b)–(e) from Sample B.
