Re-entrant charge order in overdoped (Bi,Pb)$_{2.12}$Sr$_{1.88}$CuO$_{6+\delta}$ outside the pseudogap regime

TL;DR

This study reveals re-entrant incommensurate charge order in overdoped cuprate Bi2201, persisting at high temperatures and coexisting with a simple Fermi surface, challenging the view that overdoped cuprates lack collective electronic order.

Contribution

It demonstrates the presence of robust charge order in overdoped cuprates, supported by experimental measurements and theoretical modeling within a Fermi liquid framework.

Findings

Charge order persists up to 250K in overdoped Bi2201.

Charge order coexists with a single, unreconstructed Fermi surface.

Model calculations reproduce charge order considering a van Hove singularity.

Abstract

Charge modulations are considered as a leading competitor of high-temperature superconductivity in the underdoped cuprates, and their relationship to Fermi surface reconstructions and to the pseudogap state is an important subject of current research. Overdoped cuprates, on the other hand, are widely regarded as conventional Fermi liquids without collective electronic order. For the overdoped (Bi,Pb)2.12Sr1.88CuO6+{\delta} (Bi2201) high-temperature superconductor, here we report resonant x-ray scattering measurements revealing incommensurate charge order reflections, with correlation lengths of 40-60 lattice units, that persist up to at least 250K. Charge order is markedly more robust in the overdoped than underdoped regime but the incommensurate wave vectors follow a common trend; moreover it coexists with a single, unreconstructed Fermi surface, without pseudogap or nesting features, as determined from angle-resolved photoemission spectroscopy. This re-entrant charge order is reproduced by model calculations that consider a strong van Hove singularity within a Fermi liquid framework.