Observation of a Three-Dimensional Quasi-Long-Range Electronic Supermodulation in YBa2Cu3O7-x/La0.7Ca0.3MnO3 Heterostructures

TL;DR

This study reports a three-dimensional electronic supermodulation in YBCO/LCMO heterostructures, revealing long-range correlations and competition with superconductivity, which advances understanding of charge order in cuprates.

Contribution

It uncovers a novel 3D electronic supermodulation in YBCO/LCMO heterostructures with long-range correlations, challenging the conventional 2D view of charge order in cuprates.

Findings

Supermodulation exhibits nearly four lattice constants in-plane and eight out-of-plane.

It appears above the superconducting transition temperature.

The supermodulation competes with superconductivity below T_c.

Abstract

Recent developments in high-temperature superconductivity highlight a generic tendency of the cuprates to develop competing electronic (charge) supermodulations. While coupled to the lattice and showing different characteristics in different materials, these supermodulations themselves are generally conceived to be quasi-two-dimensional, residing mainly in individual CuO2 planes, and poorly correlated along the c-axis. Here we observed with resonant elastic x-ray scattering a distinct type of electronic supermodulation in YBa2Cu3O7-x (YBCO) thin films grown epitaxially on La0.7Ca0.3MnO3 (LCMO). This supermodulation has a periodicity nearly commensurate with four lattice constants in-plane, eight out-of-plane, with long correlation lengths in three dimensions. It sets in far above the superconducting transition temperature and competes with superconductivity below this temperature for electronic states predominantly in the CuO2 plane. Our finding sheds new light on the nature of charge ordering in cuprates as well as a reported long-range proximity effect between superconductivity and ferromagnetism in YBCO/LCMO heterostructures.