Measurement of dielectric loss tangent at cryogenic temperature using superconducting film resonator

We demonstrate that the superconducting filmresonator can be used to accurately and quantitativelymeasure the microwave dielectric loss tangent of a varietyof materials. Compared to traditional dielectric resonatorloaded metal cavity method, it has advantage of smallsample size (;~2–3 orders of magnitude smaller than theold method), and much higher sensitivity to measure smallloss tangent values as small as 10(-5) at around 7 GHz bandat cryogenic temperatures. This method can be utilizedwidely in study of mechanism of microwave loss at cryogenictemperature range, which is extremely important insuperconducting microwave application areas, such asnovel super quantum computers.