Hyperbolic Poincare Projection
The field of circuit QED has emerged as a rich platform for both quantum computation and quantum simulation. Lattices of coplanar waveguide (CPW) resonators realize artificial photonic materials in the tight-binding limit. Combined with strong qubit-photon interactions, these systems can be used to study dynamical phase transitions, many-body phenomena, and spin models in driven-dissipative systems. These waveguide cavities are uniquely deformable and can produce lattices and networks which cannot readily be obtained in other systems, including periodic lattices in a hyperbolic space of constant negative curvature, and the one-dimensional nature of CPW resonators leads to degenerate flat bands. In our lab, we build experimental implementations of these systems using superconducting circuits.
Postdoc and graduate student positions available! Send email to: akollar@umd.edu
Graphs May Prove Key in Search for Holy Grail of Quantum Error Correction
In February 2019, JQI Fellow Alicia Kollár, who is also an assistant professor of physics at UMD, bumped into Adrian Chapman, then a postdoctoral fellow at the University of Sydney, at a quantum information conference. Although the two came from very different scientific backgrounds, they quickly discovered that their research had a surprising commonality. They both shared an interest in graph theory, a field of math that deals with points and the connections between them. Their ensuing collaboration resulted in a new tool that aids in the search for new quantum error correction schemes—including the Holy Grail of self-correcting quantum error correction. They published their findings recently in the journal Physical Review X Quantum.
Recent Physics Grad Sees Many Roads Ahead
As Jeffrey Wack walked across the graduation stage in May 2022, he carried with him a lot of uncertainty about where to go next. His trepidation came from his voracious curiosity for a broad range of things, primarily within physics and math—the subjects of his two degrees—but also from his interests in teaching, outreach and music. The prospect of having to pick just one path forward felt confining to Wack. But that same curiosity served him extremely well during his time at the University of Maryland, and it left him with many opportunities for next steps.
Research
Flat Bands
JQI Fellow Kollár Bridges Abstract Math and Realities of the Lab
The research of JQI Fellow Alicia Kollár, who is also a Chesapeake Assistant Professor of Physics at the University of Maryland, embodies the give and take between physics and mathematics. In her lab, she brings abstract theories to life and in turn collaborates on new theorems. She has forged a research program of manipulating light on a chip, coaxing the light into behaving as though it lives on the surface of a sphere, or a mathematical abstraction known as a hyperbolic surface. She also collaborates with mathematicians, furthering both the understanding of what these chips can do and their underlying mathematics. A direct collaboration with pure mathematicians is uncommon for a physicist, particularly an experimentalist. But Kollár is no stranger to mathematics.