Universal theory of strange metals from spatially random interactions

• Published in: Science (American Association for the Advancement of Science) Vol. 381; no. 6659; pp. 790 - 793
• Main Authors: Patel, Aavishkar A., Guo, Haoyu, Esterlis, Ilya, Sachdev, Subir
• Format: Journal Article
• Language: English
• Published: Washington The American Association for the Advancement of Science 18-08-2023
• Subjects: Cuprates; Fermions; Metals; Thermodynamic properties
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.abq6011

Strange metals—ubiquitous in correlated quantum materials—transport electrical charge at low temperatures but not by the individual electronic quasiparticle excitations, which carry charge in ordinary metals. In this work, we consider two-dimensional metals of fermions coupled to quantum critical scalars, the latter representing order parameters or fractionalized particles. We show that at low temperatures (
T
), such metals generically exhibit strange metal behavior with a
T
-linear resistivity arising from spatially random fluctuations in the fermion-scalar Yukawa couplings about a nonzero spatial average. We also find a
T
ln(1/
T
) specific heat and a rationale for the Planckian bound on the transport scattering time. These results are in agreement with observations and are obtained in the large
N
expansion of an ensemble of critical metals with
N
fermion flavors.
Editor’s summary
Many correlated electron systems, such as cuprates and heavy fermion materials, host an unusual type of metallic state called the strange metal. Strange metals have transport and thermodynamic properties with temperature dependences that differ from those of ordinary metals. Devising a theory that describes all of these properties correctly remains challenging. Patel
et al
. achieved this goal by introducing disorder in the coupling constants of a model of strongly interacting systems. —Jelena Stajic
Theory accounts for the unusual temperature dependence of transport properties in strange metals.