Quantum Sensors for the Hidden Sector Extended Support (QSHSES)

1. Enhance, consolidate and exploit a new generation of ultra-low-noise superconducting microwave quantum measurement devices, including SLUG-loaded SQUID amplifiers, distributed thin-film traveling-wave parametric amplifiers, microwave photon-counting bolometers, and qubit sensors, for searching the hidden sector of particle physics. Develop and package selected technologies to TRL5. Publish the work in high-quality journals, and create direct outreach opportunities for dissemination and utilitarian exploitation.
2. Develop and understand models of the coupling of hidden sector fields to measurement devices operating at and below the standard quantum limit. Develop parametric representations of quantum electronic devices, such squeezed-state amplifiers and photon counting bolometers, and create complete system-level analysis methods for understanding the behaviour of complex quantum microwave and millimetre-wave systems. Combine with formal quantum measurement theory to assess the ability of different technologies and configurations to measure the quantum statistical state of cold radiation in microwave cavities interacting with hidden sector fields.
3. Search for axions in our dark matter halo using UK-led apparatus installed in the world-leading ADMX axion search experiment at The University of Washington, Seattle. Build a formal UK-US collaboration with the ADMX consortium, and exchange microwave quantum measurement technology and know-how where appropriate. Use the knowledge gained to help create a national facility based at a UK site. Generate publication-quality science data by the end of year 3.5 of the project.
4. Build and commission a unique national facility for searching the hidden sector with a world-leading capability that exceeds other international experiments in key mass ranges. The facility would comprise a 1 m long, 1 m bore, 8T superconducting magnetic instrumented with quantum measurement electronics operating at 10 mK. Establish facility infrastructure, and install and commission the magnet, cryogenics and first generation quantum electronics by the 3.5 year end of the project. Fully characterise performance, and run pilot axion search experiment. Beyond the duration of this award, this facility would be used for long-term deep integrations that would search for axions and enhance significantly our understanding of the hidden sector.
5. Create a coordinated community of physicists and engineers, and train a new generation of students and postdoctoral researchers in the skills necessary for hidden sector physics, such as quantum field theory and low-energy particle observation, quantum device development and packaging, quantum systems engineering, RF and microwave measurement techniques at the quantum limit, 10 mK cryogenics and high vacuum techniques, operation of ultra-sensitive apparatus in high magnetic fields, digital signal processing and data analysis taking into account quantum statistical processes.
6. Advertise and promote the UK high-field facility to the general physics and engineering communities, ensuring a rich and diverse flow of new ideas and proposals for exploiting and enhancing the facility over a 10-20 year time span.
7. Communicate to the professional physics community, lay scientific audiences, and general public, the nature and pivotal importance of hidden sector physics.
8. Further the interests of the wider quantum measurement and quantum computing community through our research. Seek impact generating results from the development and enhancement of quantum microwave and millimetre-wave devices and related technologies, promoting UK capability to stakeholders, such as other collaborations participating in the existing and planned quantum hub activities, government agencies, policy makers, and industry. For example, we see opportunities in areas as diverse as quantum communications, computing, and radar, security and health care.