Piezoelectric tunable microwave superconducting cavity

In the context of engineered quantum systems, there is a demand forsuperconducting tunabledevices, able to operate with high-quality factors at power levels equivalent to only a fewphotons. In this work, we developed a 3Dmicrowave re-entrantcavity with such characteristics ready to provide a very fine-tuning of a high-Qresonant mode over a large dynamic range. This system has an electronic tuning mechanism based on a mechanically amplifiedpiezoelectric actuator, which controls theresonator dominant mode frequency by changing thecavity narrow gap by very small displacements. Experiments were conducted at room and dilutionrefrigerator temperatures showing a large dynamic range up to 4 GHz and 1 GHz, respectively, and were compared to afinite element method model simulated data. At elevatedmicrowave power input, nonlinear thermal effects were observed to destroy thesuperconductivity of thecavity due to the largeelectric fields generated in the small gap of the re-entrantcavity.

Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: N. C. Carvalho, Y. Fan and M. E. Tobar Source Type: research