The Anthony J Leggett Institute for Condensed Matter Theory Seminar, Jaewon Kim

Title : Linear in T and B Relaxation in Strange Metals 

Abstract:: Strange-metal behavior appears across a broad range of strongly correlated systems, including cuprates, heavy-fermion compounds, and moiré materials. Its hallmark is anomalous charge transport: resistivity is linear in temperature, while magnetoresistance is frequently linear in magnetic field. Both behaviors sharply depart from conventional Fermi-liquid expectations of T^2 resistivity and quadratic low-field magnetoresistance. Understanding the microscopic origin of this unusually rapid current relaxation remains a central challenge.

In this talk, I will show how isolated hot spots generated by coupling to density-wave fluctuations—commonly found in cuprates near optimal doping—can naturally produce both transport anomalies. In a magnetic field, cyclotron motion repeatedly carries fermions to the hotspots, where they undergo strong backscattering from density-wave fluctuations. The resulting current-relaxation rate is set by the cyclotron frequency, giving rise to linear magnetoresistance. At finite temperature, rapid scrambling and mixing between the cold regions of the Fermi surface and the hotspots enable the otherwise long-lived cold fermions to relax, producing T-linear resistivity. This mechanism therefore offers a unified microscopic origin for linear-in-B and linear-in-T transport in strange metals.

Zoom Link: https://illinois.zoom.us/my/icmt.seminar?pwd=ZU1KbnBLeXZLUmJKc0oyU205cDNDdz09

Meeting ID: 791 382 8328

Password: 106237