Other

Snapshots are the standard data produced in many quantum simulators. In this talk we demonstrate that they encode far more information than conventional correlation functions. I’ll show how snapshot data can probe conformal boundaries and defects in quantum many-body systems. In particular, from local-spin snapshots we can extract the universal conformal defect (boundary) entropy of the Ising CFT, as well as the “line of defect fixed points”. The protocol extends naturally to higher-dimensional CFTs. I’ll then discuss a construction of a strongly interacting spin-liquid wave function using free or weakly interacting fermions available on current simulators, and I’ll share preliminary results applying our proposal to real experimental data.

I will discuss the phenomenology of superconductors hosting both order parameter vortices and fractionally charged anyon excitations. I will demonstrate that in such systems superconductivity and topological order are intertwined under applied magnetic fields, leading to surprising observable consequences departing from traditional superconductivity from electronic pairing. In particular,  I will show that vortices nucleated by perpendicular magnetic fields must trap anyons in their cores. However, because only some vortices can trap an integer number of anyons, this places a constraint on the vortex phase winding. In general, rather than the expected hc/2e quantization of superconducting vortices, we find instead the enhanced flux quantum of hc/e, which I will argue should affect a wide range of observables. I will further develop a general Landau-Ginzburg theory describing vortex fluctuations and discuss the phase diagram as perpendicular magnetic field is increased, showing that condensation of the intertwined vortices leads to exotic insulating phases hosting neutral anyons and a nonvanishing thermal Hall effect.

Author Patchen Barss in conversation with Emily Petroff, Director, Public Affairs at Perimeter Institute, on the topic of his new book: The Impossible Man: Roger Penrose and the Cost of Genius.

Theatre talk with Atrium portion to follow.