Fragile charge order in the non-superconducting ground state of the underdoped high temperature superconductors

TL;DR

This study investigates the fragile charge order in underdoped high-temperature superconductors, revealing similar Fermi surface features in YBa2Cu4O8 despite the absence of charge order signatures, suggesting magnetic field effects and unconventional symmetry play roles.

Contribution

It demonstrates that Fermi surface reconstruction occurs in YBa2Cu4O8 without detectable charge order signatures, indicating a different mechanism or fragile charge order compared to related compounds.

Findings

Similar Fermi surface properties in YBa2Cu4O8 and YBa2Cu3O6+x

Charge order may be enhanced by magnetic fields in YBa2Cu4O8

Charge order in YBa2Cu4O8 is fragile and possibly unconventional

Abstract

The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied magnetic fields, together with complementary spectroscopic measurements in the hole underdoped copper oxide superconductors, point to a nodal electron pocket from charge order in YBa2Cu3O6+x. Here we report quantum oscillation measurements in the closely related stoichiometric material YBa2Cu4O8, which reveal similar Fermi surface properties to YBa2Cu3O6+x, despite an absence of charge order signatures in the same spectroscopic techniques such as x-ray diffraction that revealed signatures of charge order in YBa2Cu3O6+x. Fermi surface reconstruction in YBa2Cu4O8 is suggested to occur from magnetic field enhancement of charge order that is rendered fragile in zero magnetic fields because of its potential unconventional symmetry, and/or its occurrence as a subsidiary to more robust underlying electronic correlations.