Buried electrode geometry for lowering surface losses in superconducting microwave circuits

摘要

Embodiments are directed to a superconducting microwave circuit. The circuit includes a substrate and two electrodes. The latter form an electrode pair dimensioned so as to support an electromagnetic field, which allows the circuit to be operated in the microwave domain. The substrate exhibits a raised portion, which includes a top surface and two lateral surfaces. The top surface connects the two lateral surfaces, which show respective undercuts (on the lateral sides of the raised portions). Each of the electrodes includes a structure that includes a potentially superconducting material. Two protruding structures are accordingly formed, which are shaped complementarily to the respective undercuts. This way, the shaped structure of each of the electrodes protrudes toward the other one of the electrodes of the pair.