Strange metal from incoherent bosons

TL;DR

This paper proposes a model for the strange metal phase in cuprates involving incoherent bosons from pair density waves, explaining linear resistivity, incoherent transport, and magnetoresistance phenomena.

Contribution

It introduces a novel bosonic excitation model from pair density waves that captures key strange metal properties and recent experimental observations.

Findings

Reproduces linear temperature dependence of resistivity.

Shows bosons are incoherent, explaining Hall conductivity suppression.

Accounts for linear in-field magnetoresistance observed experimentally.

Abstract

The breakdown of the celebrated Fermi liquid theory in the strange metal phase is the central enigma of correlated quantum matter. Motivated by recent experiments reporting short-lived carriers, along with the ubiquitous observations of modulated excitations in the phase diagram of cuprates, we propose a model for this phase. We introduce bosons emerging from the remnants of a pair density wave as additional current carriers in the strange metal phase. These bosonic excitations are finite momentum Cooper pairs and thus carry twice the electronic charge, and its net spin can either be zero or one arising from the two spin-$1/2$ electrons. We show that such a model can capture the famous linear relationship of resistivity with temperature and manifests the Drude form of ac-conductivity with a Planckian dissipation rate. Furthermore, such bosons are incoherent and hence do not contribute to the Hall conductivity. The bosons emerging from the electron pairs of spin-triplet symmetry also reproduce the recently observed linear in-field magnetoresistance [P. Giraldo-Gallo et al., Science 361, 479 (2018); J. Ayres et al., arXiv: 2012.01208 (2020)].