Shot noise in a strange metal

• DOI: 10.1126/science.abq6100
• Publication Date: 2023-11-23T19:01:20Z
• Authors: Liyang Chen; Dale T. Lowder; Emine Bakali; Aaron Maxwell And...; Werner Schrenk; Monika Waas; Robert Svagera; Gaku Eguchi; Lukas Prochaska; Yiming Wang; Chandan Setty; Shouvik Sur; Qimiao Si; Silke Paschen; Douglas Natelson
• Keywords: 0301 basic medicine; Condensed Matter - Strongly Correlated Electrons; 03 medical and health sciences; Condensed Matter - Mesoscale and Nanoscale Physics; metal; nanowires; Strongly Correlated Electrons (cond-mat.str-el); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); FOS: Physical sciences; YbRh2Si2; superconductors

S trange-metal behavior has been observed in materials ranging from high-temperature superconductors to heavy fermion metals. In conventional metals, current is carried by quasiparticles; although it has been suggested that quasiparticles are absent in strange metals, direct experimental evidence is lacking. We measured shot noise to probe the granularity of the current-carrying excitations in nanowires of the heavy fermion strange metal YbRh 2 Si 2 . When compared with conventional metals, shot noise in these nanowires is strongly suppressed. This suppression cannot be attributed to either electron-phonon or electron-electron interactions in a Fermi liquid, which suggests that the current is not carried by well-defined quasiparticles in the strange-metal regime that we probed. Our work sets the stage for similar studies of other strange metals.