New tools to decipher strange metals

Strange metal behavior–best known as linear-in-temperature electrical resistivity at low temperatures instead of the normal Fermi liquid square-in-temperature one occurs across many classes of quantum materials [1,2]. Its full understanding is a major challenge. Heavy fermion compounds are particularly versatile model materials for studying this physics: they are comparatively simple, clean, and highly tunable, and several characteristics beyond linear-in-temperature resistivity have already been identified. I will give an overview and highlight recent results, including dynamical scaling of the terahertz conductivity [3], strongly suppressed shot noise [4,5], and a quantum Fisher information analysis of inelastic neutron scattering data, which provides the first evidence of high multipartite entanglement in the strange metal state [6]. I will highlight the new opportunities offered by quantum information-inspired approaches and discuss the prospect of achieving a universal understanding across strange metal platforms.

[1] S. Paschen and Q. Si, Nat. Rev. Phys. 3, 9 (2021).

[2] J. G. Checkelsky, B. A. Bernevig, P. Coleman, Q. Si, and S. Paschen, Nat. Rev. Mater. 9, 509 (2024).

[3] L. Prochaska et al., Science 367, 285 (2020).

[4] L. Chen et al., Science 382, 907 (2023).

[5] Y. Wang et al., Phys. Rev. Research 6, L042045 (2024).

[6] F. Mazza et al., arXiv:2403.12779 (2024).