Allen Scheie

Dr. Allen Scheie is a staff scientist at Los Alamos National Laboratory studying quantum materials with neutron scattering, focusing especially on correlated electron materials and quantum entanglement witnesses. Before joining Los Alamos in 2022, Dr. Scheie worked as a postdoctoral research associate at Oak Ridge National Laboratory, and before that obtained his PhD at Johns Hopkins University under Dr. Collin Broholm.

Title: Witnessing quantum spin entanglement with neutron scattering
Abstract: Electron entanglement is ubiquitous in solid state quantum materials, underpinning exotic states like superconductivity and quantum spin liquids. However, entanglement has been historically very difficult to experimentally measure, which hampers our understanding of such states. In principle, he two-point correlations measured in magnetic neutron scattering encode entanglement information. We have recently shown, using both 1D and 2D materials, that various entanglement witnesses can be extracted from neutron scattering data: one-tangle, two-tangle, and quantum Fisher Information. I will go through several examples of how the entanglement witnesses give detailed and model-independent insight into quantum materials, and end by defining open problems and future directions for this work.