Topochemically-engineered coexistence of charge and spin orders in intercalated endotaxial heterostructures

TL;DR

This study demonstrates that nanoscale intercalated heterostructures can stabilize coexistence of long-range magnetism and charge density waves in a single 2D material, enabling control over quantum phases.

Contribution

It introduces a novel metastable 2D crystal, T/H-Fe$_x$TaS$_2$, that stabilizes competing electronic orders through topochemical intercalation.

Findings

Fe intercalation induces ferromagnetism in the heterostructure.

The charge density wave persists to room temperature.

Fe content tunes both spin and charge orderings.

Abstract

Correlated electron systems that host multiple electronic orders offer routes to multifunctional quantum materials, but strong competition between these orders often prevents their coexistence. Here we show that nanoscale, metastable intercalated heterostructures can stabilize a rare combination of long-range magnetism and a commensurate charge density wave (C-CDW) order in a single material. We synthesize a two-dimensional (2D) metastable crystal, T/H-Fe$_x$TaS2, which comprises an endotaxial polytype heterostructure of 1T-TaS$_2$ and H-TaS$_2$ with Fe intercalated in the van der Waals interfaces. In T/H-Fe$_x$TaS2, Fe intercalants provide localized spins that support ferromagnetism, while 1T layers host a robust commensurate charge density wave (C-CDW) that persists to room temperature. In these intercalated heterostructures, Fe content simultaneously tunes ordering of spin and charge degrees of freedom, positioning topochemically-prepared intercalated endotaxial heterostructures as a route to stabilize and control competing quantum phases in 2D materials.