Princeton Quantum Sensing (PQS) Seminar

Recent advances in both theory and technology for Quantum Information Sciences has provided new tools to create and manipulate quantum states. This new ability is already having impact in the area of precision measurements for fundamental physics, and at least three experiments (LIGO, VIRGO, and HAYSTAC) have practically accelerated measurements by the use of squeezed states and measurement better than the Standard Quantum Limit (SQL). At the same time, recent theoretical advances have provided clear targets for measurements to address the question of nature of dark matter, which is one of the most vexing problems in physics. It is provably true that some of these targets cannot be achieved within a reasonable timescale without the use of measurements better than the SQL. The combination of this new capability and this well-defined need provide an interesting opportunity for the physics community.

I will discuss in particular the SQL-evading measurements needed for a comprehensive search for one of the most well-motivated dark matter candidates: the QCD axion. This candidate has a well motivated mass range and coupling strength to standard-model forces that is consistent with the solution of the Strong CP problem in QCD and also the observed abundance of dark matter in the galaxy. The community has the opportunity to fully survey the well-motivated mass range for the QCD axion, but only if different types of SQL evading measurements are deployed in experiments in different mass ranges. I will describe these measurements, and focus in particular on the measurements in development for the Dark Matter Radio, which composes several experiments in the mass range below 0.8 micro-eV. In particular, I will describe progress on developing the RF Quantum Upconverter (RQU), which will evade the SQL for electromagnetic measurements through backaction evasion. The RQU operates by phase-sensitive upconversion of electromagnetic signals between ~kHz and ~200 MHz to sidebands of a ~6 GHz superconducting resonator, a frequency where superconducting quantum technology is mature and available. I will describe the prospects for quantum acceleration in DM Radio.