CM-AMO Seminar | Witnessing Quantum Entanglement in Solid-State Materials

The rapidly developing field of quantum materials calls for increasingly precise methods to characterize and control entanglement. While foundational progress was first achieved in quantum optics and few-body quantum simulators, extending these ideas to complex many-body states in correlated materials remains a major challenge. In this talk, I will introduce the entanglement-witness framework as a practical route for characterizing entanglement through experimentally accessible solid-state measurements. I will begin with the Bell test and discuss how its underlying logic can be generalized to entanglement witnesses in material systems. Recent examples include the detection of spin entanglement in quantum magnets using neutron scattering and spin-orbital entanglement using resonant inelastic x-ray scattering. These approaches can also be extended to nonequilibrium settings, opening opportunities to manipulate entanglement with light. In the second half of the talk, I will move beyond distinguishable local degrees of freedom and consider entanglement among indistinguishable fermions. This motivates a generalized framework for multipartite electronic entanglement based on the cumulant reduced density matrix and nonlinear spectroscopic responses. With this strategy, we can further connect transport-noise measurements in cryogenic materials to an electronic entanglement metric, enabling the certification of entanglement in the fractional Chern insulating state of twisted MoTe2.

Bio: Yao Wang is an associate professor in Emory University. He received bachelor's degree from University of Science and Technology of China in 2011 and Ph.D. degree from Stanford University in 2017. After that, he worked at Harvard University as an MPHQ postdoctoral fellow. In 2020, he started his independent career as an assistant professor at Clemson University and then the College of Science Dean's assistant professor. He moved his group to Emory University in August 2023 and obtained tenure in 2026. His research interests lie in the theoretical and computational study of quantum many-body problems and their experimental correspondence in solid-state materials and quantum science. He was the recipient of the DOE early career award, AFOSR young investigator award, and the Scialog fellow.