Differentiation of Site-Specific Symmetry Breaking Orders in Y$_{1-x}$Pr$_x$Ba$_2$Cu$_3$O$_{6+y}$

TL;DR

This study uses site-sensitive resonant elastic x-ray scattering to distinguish between two nearly identical symmetry-breaking orders in a cuprate superconductor, revealing their different atomic site origins and temperature behaviors.

Contribution

It demonstrates the ability to differentiate similar symmetry-breaking orders in cuprates using advanced x-ray scattering techniques, clarifying their distinct atomic site characteristics.

Findings

Two distinct orders with similar symmetry in Y$_{1-x}$Pr$_x$Ba$_2$Cu$_3$O$_{6+y}$

Charge order differs from super-lattice structure at the atomic site level

Symmetry breaking at Pr-site inhibits superconductivity

Abstract

Solid matter is classified through symmetry of ordering phenomena. Experimentally, this approach is straightforward, except when distinct orderings occur with identical or almost identical symmetry breaking. Here we show that the cuprate system Y$_{1-x}$Pr$_x$Ba$_2$Cu$_3$O$_{6+y}$ hosts two distinct orderings with almost identical translational symmetry breaking. Only when applying site-sensitive resonant elastic x-ray scattering (REXS), charge ordering can be conclusively differentiated from a super-lattice structure. These two orderings occur with almost the same in-plane symmetry but manifest at different atomic sites and display different temperature dependence. Differentiating these orders provides an important clue to the anomalous behavior of PrBa$_2$Cu$_3$O$_7$ within the 123-series of high-temperature superconductors. We conclude that the symmetry breaking at the Pr-site is unfavorable for superconducting pairing.