Liyang Chen, Dale T. Lowder, Bakali, E., Andrews, A. M., Schrenk, W., Waas, M., Svagera, R., Eguchi, G., Prochaska, L., Yiming Wang, Setty, C., Shouvik Sur, Si, Q., Bühler-Paschen, S., & Douglas Natelson. (2022). Shot noise indicates the lack of quasiparticles in a strange metal. arXiv. https://doi.org/10.48550/arXiv.2206.00673
E138-04 - Forschungsbereich Quantum Materials E138 - Institut für Festkörperphysik
solid state physics; intermetallic compounds; strongly correlated electron systems
Understanding of strange metal properties, observed in materials from the high-temperature superconductors to heavy fermion metals and van der Waals structures, is an outstanding challenge. In conventional metals, current is carried by quasiparticles with charge of magnitude e, and while it has been suggested that quasiparticles are absent in strange metals, direct experimental evidence is lacking. Shot noise probes the granularity
of the current-carrying excitations. We examine nanowires of the heavy fermion strange metal YbRh 2 Si2 and discover strongly suppressed shot noise compared to conventional metals. This suppression can neither be attributed to electron-phonon interactions nor to electron-electron interactions in a Fermi liquid and therefore reveals that the current is
not carried by well-defined quasiparticles. Our work sets the stage for similar studies on other strange metals, to test the universality of this result.