Phase Instability amid Dimensional Crossover in Artificial Oxide Crystal

TL;DR

This study demonstrates a controlled metal-insulator transition in atomically engineered 2D SrRuO3 superlattices, revealing how dimensionality reduction affects electronic and magnetic phases.

Contribution

It introduces a method to induce and control phase transitions in artificial oxide crystals through atomic-scale thickness modulation.

Findings

Successful synthesis of genuine 2D SrRuO3 with suppressed charge transfer

Observation of a thermally-driven metal-insulator transition in 2D SrRuO3

Detection of a metamagnetic transition linked to electronic and magnetic instabilities

Abstract

Artificial crystals synthesized by atomic-scale epitaxy provides the ability to control the dimensions of the quantum phases and associated phase transitions via precise thickness modulation. In particular, reduction in dimensionality via quantized control of atomic layers is a powerful approach to revealing hidden electronic and magnetic phases. Here, we demonstrate a dimensionality-controlled and induced metal-insulator transition (MIT) in atomically designed superlattices by synthesizing a genuine two dimensional (2D) SrRuO3 crystal with highly suppressed charge transfer. The tendency to ferromagnetically align the spins in SrRuO3 layer diminishes in 2D as the interlayer exchange interaction vanishes, accompanying the 2D localization of electrons. Furthermore, electronic and magnetic instabilities in the two SrRuO3 unit cell layers induce a thermally-driven MIT along with a metamagnetic transition.