We Finally Know more Why Quantum ‘Strange Metals’ Are So Strange

Don't be a stranger! 😊

"For nearly 40 years, materials called ‘strange metals’ have flummoxed quantum physicists, defying explanation by operating outside the normal rules of electricity. ...

The surprisingly simple new theory explains many oddities about strange metals, such as why the change in electrical resistivity — a measure of how easily electrons can flow through the material as electrical current — is directly proportional to the temperature, even down to extremely low temperatures. That relationship means that a strange metal resists the flow of electrons more than an ordinary metal such as gold or copper at the same temperature.

The new theory is based on a combination of two properties of strange metals. First, their electrons can become quantum mechanically entangled with one another, binding their fates, and they remain entangled even when distantly separated.
Second, strange metals have a nonuniform, patchwork-like arrangement of atoms. ...
a better understanding of strange metals could help physicists develop and fine-tune new superconductors for applications such as quantum computers. ..."

From the editor's summary and abstract:

"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 dependencies 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.

Abstract

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."

We Finally Know Why Quantum ‘Strange Metals’ Are So Strange A new study led by the Flatiron Institute’s Aavishkar Patel has identified a mechanism that explains the unusual behavior of strange metals, considered one of the greatest open challenges in condensed matter physics.

Universal theory of strange metals from spatially random interactions (no public access)