Dr. Nathanan Tantivasadakarn
California Institute of Technology
From Wave-Function Collapse and Galois Solvability to the Realization of Non-Abelian Topological Order on a Quantum Device
Location: 1080 Physics Research Building, Smith Seminar Room
Faculty Host: Yuan-Ming Lu, Kyle Kawagoe
Abstract: I will review our recent set of theoretical works on efficiently preparing long range quantum entanglement with adaptive quantum circuits: the combination of measurements with unitary gates whose choice can depend on previous measurement outcomes. I will show that this additional ingredient can be leveraged to prepare the long sought-after non-Abelian topological phases with a circuit depth that is independent of system size. Using this framework, we uncover a complexity hierarchy of long-range entangled states based on the minimal number of measurement layers required to create the state. Moreover, we find that certain non-Abelian states that cannot be efficiently prepared with adaptive circuits have a surprising connection to the unsolvability of the quintic polynomial.
Finally, I will describe our recent collaboration with Quantinuum where we present the first unambiguous realization of non-Abelian D4 topological order and demonstrate control of its anyons. In particular, we are able to detect a non-trivial braiding where three non-Abelian anyons trace out the Borromean rings in spacetime, a signature unique to non-Abelian topological order.
Bio: Nat Tantivasadakarn obtained his Ph.D. from Harvard University and is currently a Burke postdoctoral fellow at Caltech. His research interests range from topological phases of matter to quantum error correction and computation, and their dynamical generalizations.
Students and postdocs are invited to stay and chat with the speaker from 11:30-12:00.