Extracting Quantum Entanglement Witnesses from Magnetic Pair Distribution Function Data on Quantum Magnets

Quantum entanglement, the phenomenon where two or more quantum states are intrinsically linked such that their states cannot be expressed as the product of single-particle states, is a foundational principle of quantum information technologies. While methods for quantifying few-body entanglement are well established, probing many-body entanglement remains a challenge. Entanglement witnesses, quantitative measures of the level of entanglement in a system, have been shown to be calculable from neutron scattering data collected from certain crystalline materials with unconventional magnetic ground states. We demonstrate that mathematical methods, including magnetic pair distribution (mPDF) analysis, can be used to extract certain entanglement witnesses from powder sample neutron scattering data, specifically that of a frustrated triangular lattice antiferromagnet, NaYbO₂.