We are an experimental research group that conducts research at the interface of Atomic, Molecular, and Optical (AMO) and condensed matter physics. We use nano-fabrication techniques to construct superconducting quantum circuits that allow us to probe fundamental questions in quantum mechanics.
Our research group is focused on understanding and controlling open quantum systems. These are quantum systems that necessarily interact with their environment, a process that can be deleterious to the quantum properties of the system, but can also be harnessed for control and to induce desired dynamics. In studying these systems, we hope to develop new ways of using precision quantum measurement to study novel phases of condensed matter, prepare quantum states, and probe chemical and biological systems.
Superconducting qubits are a promising system for the realization of quantum schemes for computation, simulation, and data encryption. While the fabrication of these systems allows for exquisite control over the properties of the quantum systems, their complex material nature results in coupling to uncontrolled degrees of freedom in the surrounding environment, eventually leading to decoherence of some states of these systems. Our research focuses on engineering the quantum system-environment interaction to preserve coherence, to prepare complex many body states, and to create interfaces with atomic systems such as cold neutral atoms, trapped ions, and solid state spins such as nitrogen vacancy centers in diamond.
(December 2015) Mapping Quantum Trajectories in Spontaneous Emission:
(March 2016) State-signal Correlations: Exploring time symmetry in quantum measurement.
(April 2015) Kater wins the Sloan Fellowship in Physics
Read the Washington University Press Release.(March 2015) The Past Quantum State: "Prediction and retrodiction for a continuously monitored superconducting qubit".
Popular Coverage of the paper:
Washington University Record: "In the quantum world, the future affects the past" D. Lutz (Feb 2015)
Science News: "Quantum guessing game uses the future to predict the past", A. Grant, (Feb 2015)
International Business Times: "Time runs bizarre in quantum world where past is changed by the future", Jayalakshmi K, (Feb 2015)
Daily Mail: "Can the past be changed by the FUTURE?", E. Zolfagharifard, (Feb 2015)
"Mapping the optimal route between two quantum states" by S. J. Weber, A. Chantasri, J. Dressel, A. N. Jordan, K. W. Murch, and I. Siddiqi.
Read it on arxiv or in Nature.
Some press releases related to the paper:
Washington University in St. Louis: Finding Quantum Lines of Desire
UC Berkeley: Watching Schrodinger's Cat Die
University of Rochester: Mapping the Optimal Route between Two Quantum States
Nature: News & Views by Adrian Lupascu Quantum physics: The path most travelled
Huffington post: Robert Sanders
Live Science: Quantum Particles Take the Road Most Traveled