We autonomously stabilize arbitrary states of a qubit through parametric modulation of the coupling between a fixed frequency qubit and resonator. The coupling modulation is achieved with a tunable coupling design, in which the qubit and the resonator are connected in parallel to a superconducting quantum interference device. This allows for quasistatic tuning of the […]
Nonequilibrium phase transitions pose many questions and challenges, in part due to their complexity in theoretical descriptions, in part due to the experimental difficulties in systematically controlling systems out of equilibrium. In work now published in a new PRX article, the Houck Lab has studied a chain of 72 microwave cavities, each coupled to a […]
In a new preprint, we show how to implement a quantum optimal control algorithm with automatic differentiation executed on a GPU. This work, done in collaboration with the Schuster Lab, highlights how automatic differentiation allows one to specify advanced optimization criteria and incorporate them in the optimization process with ease. We demonstrate that the use […]
While measurements of global system properties are often readily obtained, measurements of more detailed local properties can provide a deeper understanding of the system at hand on a microscopic level. However, measuring local properties is often difficult. One solution is to use scanning probe measurements in which a probe is dragged across the surface of […]
Photons are particles with rather special properties. They are easily created by a light source, absorbed by matter, and may repel or attract each other when in contact with a suitable material. The idea of feeding photons into crystal-like structures in which photons move between preferred positions and interact with each other, has recently captured […]
Mohamed has been awarded the 2016 Wayne C. Booth Graduate Student Prize for Excellence in Teaching by the University of Chicago! The Wayne C. Booth Graduate Student Prize for Excellence in Teaching was established in 1991 in honor of Wayne C. Booth, the George M. Pullman Distinguished Service Professor in English Language & Literature and […]
Nicholas has been awarded a Weinberg College Summer Research Grant! This award is made possible by the generous support of the Richman Fund for Undergraduate Research and Weinberg College of Arts and Sciences alumni.
Andy Li presents his research during a poster session at the Northwestern site visit by the NSF MPS Directorate. (Photo credit: Roger Anderson)
The problem of interacting bosons in frustrated lattices is an intricate one due to the absence of a unique minimum in the single-particle dispersion where macroscopic number of bosons can condense. In this paper, we consider a family of tight-binding models with macroscopically degenerate lowest energy bands, separated from other bands by a gap.We predict […]
Microwave photons inside lattices of coupled resonators and superconducting qubits can exhibit surprising matter-like behavior. Realizing such open-system quantum simulators presents an experimental challenge and requires new tools and measurement techniques. Here, we introduce Scanning Defect Microscopy as one such tool and illustrate its use in mapping the normal-mode structure of microwave photons inside a […]