Electric field driven octahedral rotation in perovskite

TL;DR

This paper demonstrates that electric fields can induce and control octahedral rotations in perovskite Sr$_2$RuO$_4$, enabling in situ tuning of its physical properties through surface electric field manipulation.

Contribution

It reveals that electric fields can drive and modulate octahedral rotations in Sr$_2$RuO$_4$, providing a new method for controlling perovskite properties.

Findings

Electric field induces octahedral rotation in Sr$_2$RuO$_4$ surface layers.

Surface K dosing restores unrotated structure, showing control over rotation.

Theoretical analysis links surface electric field to octahedral rotation.

Abstract

Rotation of MO6 (M = transition metal) octahedra is a key determinant of the physical properties of perovskite materials. Therefore, tuning physical properties, one of the most important goals in condensed matter research, may be accomplished by controlling octahedral rotation (OR). In this study, it is demonstrated that OR can be driven by an electric field in Sr$_2$RuO$_4$. Rotated octahedra in the surface layer of Sr$_2$RuO$_4$ are restored to the unrotated bulk structure upon dosing the surface with K. Theoretical investigation shows that OR in Sr$_2$RuO$_4$ originates from the surface electric field, which can be tuned via the screening effect of the overlaid K layer. This work establishes not only that variation in the OR angle can be induced by an electric field, but also provides a way to control OR, which is an important step towards in situ control of the physical properties of perovskite oxides.