Searching for Dark Matter with Squeezed and Entangled Microwave Fields

Abstract

Recent experiments show that quantum enhanced sensing methods can benefit searches for hypothetical dark matter particles such as axions and dark photons. These quantum enhanced experiments use superconducting circuits to measure and manipulate the quantum state of the microwave cavities that couple to the hypothetical dark matter. In this talk, I’ll describe several concepts that make use of entanglement and squeezing to speed up the search for dark matter. These concepts already double the quantum-limited search rate in an axion search, but with the fragile nature of squeezed states precluding much larger speed-ups. To go beyond the modest speed-ups already demonstrated, future experiments should consider quantum enhanced methods during the initial design, rather than adding them to existing experiments. Indeed, learning to use these quantum enhanced measurement concepts most effectively in dark matter searches is a new frontier of experiment design.