Dissertation Research
Princeton University
Anticipated Defense: December 2026
My thesis work has been in operationalizing sub-GHz Kinetic Inductance Traveling Wave Parametric Amplifiers (KI-TWPAs) for the Princeton Axion Search (PXS). PXS is laboratory-scale search for a dark matter particle candidate, the axion, at mass ranges the correspond to the transitional region between lumped-element and cavity haloscope search techniques.
The PXS search range poses unique challenges in developing quantum-limited readout schemes. The sensitivity requirements demand noise levels that approach the quantum limit, and significant operational bandwidth as the experiment sweeps through the search regime. Commerically available high electron mobility transistor (HEMT) amplifiers posses the bandwidth, but are 100 to 1000x above the target noise performance. Reflection-based, parametric amplifiers such as Josephson Parametric Amplifiers meet the noise requirements, but have narrow bandwidth that requires tuning prodedures that lead to significant experiment downtime.
Traveling Wave Parametric Amplifiers have emerged as a workhorse in the quantum computing community for the quantum-limited noise and huge operational bandwidth. Our challenge is to operationalize new versions of these amplifiers that produce gain at lower frequencies by screening devices, designing infrastructure, and making state-of-the-art noise measurements. Our work enables PXS to search for axions, and establishes a low-noise, high-gain, high-saturation power amplifier for sub-GHz quantum computing architectures.
Some of the work we provide in this effort is custom cabling that achieves greater gain and bandwidth through improved impedance matching, designing lumped-elemet microwave filters made from superconducting traces, and noise-temperature measurement techniques that provide the necessary precision to make measurements approaching the standard quantum limit.
Laboratory Work
A collection of research efforts outside of publication have been:
- Developing commercial grade Cryogenic Coax - Developed laboratory methods to fabricate stainless steel, copper, and superconducting Niobium-Titanium coaxial cable that outperformed commercially available product.
- Analog Control Circuits for Cryogenic Microwave Switches - Designed and fabricated an analog control circuit and command line interface to operate microwave multi-pole switches at sub-kelvin temperatures.
- Designing High-Current leads for Cryogenic Magnets - Designed and tested current leads that carried 300 Amps to 4K in a conduction-cooled cryostat
- Laboratory Software Development - Hosted GitLab, integrated Grafana and InfluxDB for timeseries data, wrote variety of python and shell control scripts to automate experiments.
PXS Publications
Our recent group publications include:
- Passive pyrolytic graphite heat switch for sub-Kelvin coolers - We achieved a mechanism to replace expensive gas-gap heat switches with inexpensive grapihte sheet for thermal connections that do not require an active switch