Quantum optomechanics, gravitational wave detection, and analogue gravity all lean on a common substrate of enabling technologies: superconducting microwave resonators with high quality factors, low-loss filters and routing, and parametric amplifiers operating near the standard quantum limit. We design, fabricate, and characterise these components — both as research outputs in their own right and as the supporting infrastructure of our experiments.
Our work spans coplanar-waveguide and three-dimensional re-entrant resonator architectures, optimised for compatibility with mechanical resonators and superfluid-helium environments at millikelvin temperatures. We characterise the dominant loss mechanisms — two-level systems in dielectric interfaces, vortex motion in superconducting films, radiation losses — and design geometries that minimise their contribution to the measurement chain. Some of this work has been carried out in room-temperature settings, where novel cavity architectures can be prototyped and benchmarked before being adapted to the cryogenic environment.
Beyond resonators, we are interested in the practical aspects of making complex microwave circuits work reliably inside dilution refrigerators: thermalisation, packaging, magnetic shielding, and the integration of multiple high-frequency components in a single experiment. This translational work feeds back directly into the research programmes on superfluid optomechanics and fundamental-physics detectors.
- Loss-engineered superconducting resonators for optomechanical readout
- Compact, low-noise parametric amplification at millikelvin temperatures
- Robust packaging and thermalisation strategies for dilution-refrigerator experiments
- Integration of superconducting circuits with superfluid-helium environments and mechanical resonators