General Physics Colloquium and Parratt Lecture, Professor Jon Simon, Stanford University

Title:  Probing Photonic Quantum Matter with Cats

Host:  Abigail Crites

Abstract:  I will describe work in the Simon/Schuster collaboration building fluids of light. Starting with the analogy between photons in a lattice of cavities and electrons in the ionic lattice comprising a solid, I will then describe our explorations of this physics in a superconducting circuit, building crystals of light using reservoir engineering, and more recently, adiabatically preparing liquids. I will then introduce a protocol whereby we control what fluid state we prepare with a qubit; by undoing this qubit-fluid entanglement and sandwiching this entanglement/disentanglement protocol within a Ramsey sequence, we are able to learn about the manybody system by measuring only the qubit. We use this new tool as a thermodynamic probe of the manybody system, and even enhance its coherence through spin-echo, leading us to the question: can small quantum computers fundamentally change how we probe materials?