MoRe 초전도 공진기의 제작과 특성 연구

Abstract

Magnetic-field-resilient superconducting coplanar waveguide (SCPW) resonators are highly useful tools that can be applied to various superconducting information devices and sensors in that they maintain high-quality factors even under high magnetic field. However, magnetic fields degrade the quality factor of SCPW resonator by suppressing the superconductivity. And that can be realized by type Ⅱ superconductors with large Hc2. MoRe (molybdenum-rhenium) alloys are known as type Ⅱ superconductors having Tc ~ 10 K and Hc2 ~ 8 T, which is a good candidate for magnetic-field-resilient SCPW resonators. Here, we show the properties of the MoRe alloy used in this study and fabricate MoRe SCPW resonator devices of various thicknesses (15 ~ 120 nm). We demonstrate and compare the comprehensive characteristic study conducted on these devices related to characteristic magnetic field B*, which is defined as Qi(B*) = 0.5*Qi(B=0). And in particular, 27 nm thick device maintain Qi > 10^4 for B* ~ 220 mT at T = 1.8 K.