Molybdenum-Rhenium alloy based high-$Q$ superconducting microwave resonators

TL;DR

This paper reports on the fabrication and characterization of high-Q superconducting microwave resonators made from MoRe alloy, demonstrating their potential for advanced quantum and hybrid systems applications.

Contribution

It introduces MoRe alloy-based SMRs, providing detailed performance metrics and testing their compatibility with high-temperature processes and magnetic fields.

Findings

Internal quality factors up to 700,000 at low power

Presence of two-level systems affecting loss at low temperatures

Compatibility with high-temperature processes and magnetic fields

Abstract

Superconducting microwave resonators (SMR) with high quality factors have become an important technology in a wide range of applications. Molybdenum-Rhenium (MoRe) is a disordered superconducting alloy with a noble surface chemistry and a relatively high transition temperature. These properties make it attractive for SMR applications, but characterization of MoRe SMR has not yet been reported. Here, we present the fabrication and characterization of SMR fabricated with a MoRe 60-40 alloy. At low drive powers, we observe internal quality-factors as high as 700,000. Temperature and power dependence of the internal quality-factors suggest the presence of the two level systems from the dielectric substrate dominating the internal loss at low temperatures. We further test the compatibility of these resonators with high temperature processes such as for carbon nanotube CVD growth, and their performance in the magnetic field, an important characterization for hybrid systems.