Restored strange metal phase through suppression of charge density waves in underdoped YBa$_2$Cu$_3$O$_{7-\delta}$

TL;DR

This study demonstrates that suppressing charge density waves in underdoped YBa2Cu3O7−δ films restores the strange metal phase characterized by linear resistivity, highlighting strain as a tool to control quantum ground states.

Contribution

It reveals that strain-induced suppression of charge density waves can recover the strange metal behavior in underdoped cuprates, a novel approach to manipulating quantum phases.

Findings

Suppression of CDW correlates with the re-emergence of T-linear resistivity.

Strain control can manipulate the ground state of cuprate superconductors.

Charge density waves are linked to deviations from strange metal behavior.

Abstract

The normal state of optimally doped cuprates is dominated by the "strange metal" phase that shows a linear temperature ($T$) dependence of the resistivity persisting down to the lowest $T$. For underdoped cuprates this behavior is lost below the pseudogap temperature $T^*$, where Charge Density Waves (CDW) together with other intertwined local orders characterize the ground state. Here we show that the $T$-linear resistivity of highly strained, ultrathin and underdoped YBa$_2$Cu$_3$O$_{7-\delta}$ films is restored when the CDW amplitude, detected by Resonant Inelastic X-ray scattering, is suppressed. This observation points towards an intimate connection between the onset of CDW and the departure from $T$-linear resistivity in underdoped cuprates. Our results illustrate the potential of using strain control to manipulate the ground state of quantum materials.