2025/03/14 by Hunter, A., Putzke, C., Kugler, F. B. +23 · 1 citation
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2503.11311
Interacting electrons can form metallic states beyond the Fermi liquid paradigm, a conceptual frontier of many-body physics mainly explored via bulk thermodynamics and transport. In contrast, the microscopics of anomalous single-particle excitations underlying non-Fermi liquid properties have largely remained in the dark. Here we spectroscopically map such quantum-critical excitations in Sr2RuO4 under uniaxial pressure, an experimental challenge overcome by technical advances combining focused ion beam micro-milling with laser angle resolved photoemission. We show that quasiparticle excitations acquire a non-Fermi liquid scattering rate near the critical point but remain remarkably robust throughout the transition. These experiments serve as a benchmark for the theory of anomalous metals and settle the long-standing question if quantum-critical systems host quasiparticle excitations.