Local Excitation of Resonance Modes in the Sub-THz Planar Resonators by AC Josephson Effect

An excitation of various resonance modes in a square open-loop resonator were studied by Josephson spectroscopy. Copper resonator with square side sizes 234 μm and 173 μm correspondingly and 5 μm cut width was explored. Using different arrangements of the resonator against planar bicrystal Josephson junction from YBa 2 Cu 3 O 7-x a number of resonances was observed in a frequency range from 60 GHz to 350 GHz. These resonances correspond to excitation of fundamental magnetic mode at frequency of 71 GHz, even plazmonic mode at frequency of 151 GHz and unhybridized plazmonic mode at frequency of 230 GHz. Experimental results were corroborated by the results of numerical simulation.