PME Special Seminar - Yao Wang

Witnessing Entanglement for Distinguishable Spins and Indistinguishable Electrons Using Solid-State Spectroscopy

The rapidly evolving quantum material science calls for precise characterization and predictive control of entanglement. This demand has evolved from quantum optics to quantum materials. My talk will introduce the recent progress in probe and control of many-body entanglements with x-ray techniques. I will start with spin entanglement witness of quantum magnets, based on the spin quantum Fisher information (QFI), using resonant inelastic x-ray scattering (RIXS) and introduce necessary theoretical considerations and corrections. I will then apply this technique into ultrafast x-ray scattering and discuss how to reconstruct instantaneous entanglement depth in a self-consistent approach. This application leads to the light-induced spin entanglement in cuprates. Finally, I will move away from entanglement of distinguishable spin modes and generalize the notion to multi-particle entanglement among indistinguishable electrons, via the cumulative reduced density matrix and the nonlinearity of RIXS.