Abstract: Models of light-matter interaction with natural atoms typically invoke the dipole approximation, wherein atoms are treated as point-like objects compared with the wavelength of their resonant driving fields. In this talk, we present a demonstration of “giant artificial atoms” realized with superconducting qubits in a waveguide QED architecture. The superconducting qubits couple to the waveguide at multiple, well-separated locations. In this configuration, the dipole approximation no longer holds, and the giant atom may quantum mechanically self-interfere. This system enables tunable qubit-waveguide couplings with large on-off ratios and a coupling spectrum that can be engineered by design. Multiple, interleaved qubits in this architecture can be switched between protected and emissive configurations, while retaining qubit-qubit interactions mediated by the waveguide. Using this architecture, we generate a Bell state with 94% fidelity, despite both qubits being strongly coupled to the waveguide. Time permitting, we also discuss recent advances in 3D integration of superconducting quantum circuits.
Bio: William D. Oliver is jointly appointed Professor of Electrical Engineering and Computer Science, Professor of Physics, and Lincoln Laboratory Fellow at the Massachusetts Institute of Technology. He serves as the Director of the Center for Quantum Engineering and as Associate Director of the Research Laboratory of Electronics. Will’s research interests include the materials growth, fabrication, design, and measurement of superconducting qubits, as well as the development of cryogenic packaging and control electronics. Will is a Fellow of the American Physical Society, Senior Member of the IEEE, serves on the National Quantum Initiative Advisory Committee and the US Committee for Superconducting Electronics, and is an IEEE Applied Superconductivity Conference (ASC) Board Member. He received his PhD in Electrical Engineering from the Stanford University in 2003.
Location: IN PERSON - Jeong H. Kim Engineering Building, Room 1110