English

Tunable non-Fermi liquid phase from coupling to two-level systems

Strongly Correlated Electrons 2024-06-11 v1 Disordered Systems and Neural Networks Statistical Mechanics

Abstract

We study a controlled large-NN theory of electrons coupled to dynamical two-level systems (TLSs) via spatially-random interactions. Such a physical situation arises when electrons scatter off low-energy excitations in a metallic glass, such as a charge or stripe glass. Our theory is governed by a non-Gaussian saddle point, which maps to the celebrated spin-boson model. By tuning the coupling strength we find that the model crosses over from a Fermi liquid at weak coupling to an extended region of non-Fermi liquid behavior at strong coupling, and realizes a marginal Fermi liquid at the crossover. Beyond a critical coupling strength, the TLSs freeze and Fermi-liquid behavior is restored. Our results are valid for generic space dimensions d>1d>1.

Keywords

Cite

@article{arxiv.2310.07768,
  title  = {Tunable non-Fermi liquid phase from coupling to two-level systems},
  author = {Noga Bashan and Evyatar Tulipman and Jörg Schmalian and Erez Berg},
  journal= {arXiv preprint arXiv:2310.07768},
  year   = {2024}
}

Comments

4.5 + 3 pages, 3 figures

R2 v1 2026-06-28T12:47:46.535Z