Superconducting Microstrip High-Q Microwave Resonators

Abstract

Superconducting miniature microstrip resonators, operating at X band, have been constructed using vacuum-deposited lead on low-loss sintered alumina substrate. Unloaded Q's as high as 200 000 and 500 000 have been measured at 14.3 GHz at 4.2 and 1.8 K, respectively.

Superconducting Microresonators: Physics and Applications

“…a ms Q r $ 8 Â 10 2 was possible, a limit that was two orders of magnitude lower than contemporary cavity measurements. DiNardo et al (53) obtained much higher quality factors, around Q r ¼ 5 Â 10 5 at 14 GHz, using thin-film lead microstrips on alumina substrates. However, the relatively thick substrates used yield low values of a ms , so the inferred value of Q s $ 5 Â 10 2 is actually similar to the limit set by Mason & Gould.…”

Superradiance of cold atoms coupled to a superconducting circuit

“…Photon escape from the resonator is due to the finite quality factor Q of the LC circuit. Unloaded Q factors of up to 5 × 10 5 have been achieved for superconducting LC circuits [24,25], leading to κ = ω/Q of the order of several kilohertz. For such a high-quality resonator and the typical coupling constants of a few hundred hertz calculated in Sec.…”

Microwave superconductivity part 1: History, properties and early applications

“…al. [11] reported on thin lead ring resonators and half wave length resonators operating at 14 GHz which exhibited unloaded Q-values of about 200,000 at 4 K and about 500,000 at 1.8 K. These values of Q are extremely difficult to realize using normal conducting materials, even for structures with very large physical dimensions.…”

“…Length of the housing was approximately 2.5 cm [11]. resonators in the readout circuits of Transition Edge Sensors (TES) devices and for Quantum Computing applications.…”