Please join us for a presentation by Dr. David Schuster of Stanford University.

His talk is titled: Assembling and probing highly entangled quantum matter with superconducting circuits

Abstract: Manipulating quantum systems composed of interacting particles represents a central challenge of modern quantum science, with applications from quantum computation to many-body physics. I will present our recent work in constructing low-entropy quantum fluids of light by employing particle-resolved assembly combined with robust adiabatic preparation. This experiment is performed in a 1D Bose-Hubbard circuit implemented with an array of capacitively coupled transmon qubits. We leverage strong lattice disorder to inject individual photons into known localized eigenstates, then adiabatically remove this disorder to melt the photons into a fluid via tunneling-induced quantum fluctuations. It is becoming increasingly clear that in the quantum regime, state preparation and characterization should not be treated separately -- entangling the two processes provides a quantum advantage in information extraction.  I will present a new approach which we term ``manybody Ramsey interferometry'' that combines adiabatic state preparation and Ramsey spectroscopy: leveraging our recently-developed one-to-one mapping between computational-basis states and manybody eigenstates, we prepare a superposition of manybody eigenstates controlled by the state of an ancilla qubit, allow the superposition to evolve relative phase, and then reverse the preparation protocol to disentangle the ancilla while localizing phase information back into it.  At the end, we can discuss ways for quantum computers to efficiently probe quantum matter.