Many-body states of quantum matter

With increasing capabilities of quantum computing hardware, we are examining new classes of many-body systems that can be engineered and explored in the laboratory. One particular area of interest is low-disorder arrays of Josephson junction, probed using modern tools of circuit quantum electrodynamics. These arrays are host to a variety of novel effects and phenomena, often driven by their ability to host persistent-current vortices when penetrated by an external magnetic field. In a tunneling-dominated energy regime, these topological excitations are classically well-defined objects. However, due to the phase-number uncertainty relation, an energy regime exists where phase and charge number quantum fluctuations are on equal footing, introducing the concept of quantum vortices.

Already our team has explored new experimental regimes of these devices, which date back to the 1990s for exploring classical phenomena in such systems, in collaboration with an experimental team at the University of Tokyo, and have begun to realize large arrays that can explore potential new phases of matter for the quantum XY model. At the same time, by zooming in on the quantum behavior of vortices, we can better understand how they may be utilized in superconducting circuits to induce circulation and improve resistance to fabrication errors and charge noise for quantum computing devices. This adaptation of condensed matter concepts to microwave engineering follows prior work from our group in developing topological photonics.

Share this post

Team Members

  • Brittany Richman