Tunable Emergent Heterostructures in a Prototypical Correlated Metal

TL;DR

This study demonstrates that in a prototypical correlated metal, spontaneous heterostructures can be tuned using small magnetic fields, revealing a pathway to designing intrinsic, controllable electronic textures in complex materials.

Contribution

The paper shows that magnetic anisotropy and superstructures in CeRhIn5 can be controlled with small magnetic fields, enabling tunable intrinsic heterostructures in correlated electron systems.

Findings

Field-induced easy-axis anisotropy is large and controllable.

Magnetic superstructures are closely linked to superconducting textures.

Tunable heterostructures can be realized in correlated materials.

Abstract

At the interface between two distinct materials desirable properties, such as superconductivity, can be greatly enhanced, or entirely new functionalities may emerge. Similar to in artificially engineered heterostructures, clean functional interfaces alternatively exist in electronically textured bulk materials. Electronic textures emerge spontaneously due to competing atomic-scale interactions, the control of which, would enable a top-down approach for designing tunable intrinsic heterostructures. This is particularly attractive for correlated electron materials, where spontaneous heterostructures strongly affect the interplay between charge and spin degrees of freedom. Here we report high-resolution neutron spectroscopy on the prototypical strongly-correlated metal CeRhIn5, revealing competition between magnetic frustration and easy-axis anisotropy -- a well-established mechanism for generating spontaneous superstructures. Because the observed easy-axis anisotropy is field-induced and anomalously large, it can be controlled efficiently with small magnetic fields. The resulting field-controlled magnetic superstructure is closely tied to the formation of superconducting and electronic nematic textures in CeRhIn5, suggesting that in-situ tunable heterostructures can be realized in correlated electron materials.