Dissertation Defense: Jacob Blumoff, Yale University, “Multiqubit experiments in 3D circuit quantum electrodynamics”

Event time: 
Thursday, May 4, 2017 - 9:00am to 10:00am
Yale Quantum Institute (YQI), YQI Seminar Room See map
17 Hillhouse Avenue
New Haven 06511
Event description: 

Circuit quantum electrodynamics (cQED) is the field of manipulating and measuring quantum electrical circuits. These circuits operate in the microwave regime, allowing use of sophisticated experimental equipment and techniques developed for industry. The nature of these devices allows for very strong interactions, providing interesting and accessible physics in the single-quantum regime. Recently, part of the field has branched from strictly lithographically designed circuits to exploit the distinctly three-dimensional electromagnetic environment. 3D components can be very high-Q compared to their 2D counterparts. This thesis explores some of the first experiments in 3D cQED to use multiple qubits, both with transmon qubits and qubits encoded in the states of harmonic oscillators. One experiment demonstrates a novel method to use a high-Q resonator to measure a register of transmon qubits in nontrivial ways. We go on to rigorously characterize these measurements. A second experiment realizes the first deterministically teleported two-qubit gate. The qubits in this experiment are encoded in harmonic oscillators. We use an entangled pair of transmons as a resource, exploiting high-fidelity measurement and real-time feedback. The tools employed in these experiments constitute a suite of capabilities necessary for increasingly complex cQED experiments.