Distilling quantum materials to effective Hamiltonians via multi-probe spectroscopy
Speaker: Dr. Yu He
Affiliation: Yale University
Date: September 17, 2026
Abstract:
Density functional theory has revolutionized material design and discovery. However,
for many materials with strong electronic and lattice interactions, mean field approximation
fails, fluctuations thrive, and lattice Hamiltonians at effective interaction level
become the de facto materials' DNA. While computational condensed matter physics has
made major progress in solving such Hamiltonians as abstracted materials, experimental
measures of interaction parameters remain scarce and challenging. We show how angle-resolved
photoemission spectroscopy (ARPES) and inelastic x-ray scattering (IXS) can become
a powerful duo to extract effective interactions in high-Tc superconductors [1], layered
magnets [2], and strongly electron-lattice coupled materials [3]. By experimentally
"distilling" materials into effective Hamiltonians, we reveal the origins of uncommon
superconductivity suppression, magnetic switching, and exotic metal-to-insulator transitions.
[1] Yang, PNAS 123, e2536919123 (2026)
[2] Li, Phys Rev Lett 136, 216503 (2026)
[3] Kang, Phys Rev Materials 10, L053201 (2026)