Join Zoom Meeting: https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09

Title: Waveform estimation and noise spectroscopy at the fundamental quantum limit

Abstract: Waveform estimation is the task of measuring a whole function rather than just a few unknown parameters. This is a canonical problem at the frontier of physics (from gravitational-wave observatories to ultralight dark matter haloscopes) and emerging technologies (from quantum imaging to profiling quantum devices). A quantum limit for waveform estimation was first proposed in a seminal paper by Tsang et al. fifteen years ago, yet this bound does not account for imperfections such as loss and noise, nor does it encompass the use of coherent quantum control or computation to improve the sensitivity. In this talk, we present new tight bounds on the linear, lossy, controlled waveform estimation task that apply in the single-shot regime and exploit joint teleportation covariance ideas developed by Pirandola et al. We will also present our recent findings in quantum-optimal noise spectroscopy, including accounting for finite energy and dead time and quantum computation.