Enhanced Ferromagnetism in Monolayer Cr2Te3 via Topological Insulator Coupling

Abstract

Exchange-coupled interfaces are pivotal in exploiting two-dimensional (2D) ferromagnetism. Due to the extraordinary correlations among charge, spin, orbital and lattice degrees of freedom, layered magnetic transition metal chalcogenides (TMCs) bode well for exotic topological phenomena. Here we report the realization of wafer-scale Cr2Te3 down to monolayer (ML) on insulating SrTiO3(111) and/or Al2O3(001) substrates using molecular beam epitaxy. Robust ferromagnetism persists in the 2D limit. In particular, the Curie temperature TC of 2 ML Cr2Te3 increases from 100 K to ~ 120 K when proximitized to topological insulator (TI) (Bi,Sb)2Te3, with substantially boosted magnetization as observed via polarized neutron reflectometry. Our experiments and theory strongly indicate that the Bloembergen-Rowland interaction is likely universal underlying TC enhancement in TI-coupled magnetic heterostructures. The topological-surface-enhanced magnetism in 2D TMC enables further exchange coupling physics and quantum hybrid studies, including paving the way to realize interface-modulated topological electronics.

Main: 9 pages, 3 figures, 1 table; SI: 4 pages, 9 figures

References in corpus (24)

• Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit
• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• Gate-tunable Room-temperature Ferromagnetism in Two-dimensional Fe${}_3$GeTe${}_2$
• Magnetic 2D materials and heterostructures
• Giant Tunneling Magnetoresistance in Spin-Filter van der Waals Heterostructures
• Ising-Type Magnetic Ordering in Atomically Thin FePS3
• Room Temperature Intrinsic Ferromagnetism in Epitaxial Manganese Selenide Films in the Monolayer Limit
• Magnetic impurities on the surface of a topological insulator
• Layered Antiferromagnetism Induces Large Negative Magnetoresistance in the van der Waals Semiconductor CrSBr
• Electrically controllable surface magnetism on the surface of topological insulator
• Ordering of magnetic impurities and tunable electronic properties of topological insulators
• Twisted exchange interaction between localized spins embedded in a one- or two-dimensional electron gas with Rashba spin-orbit coupling
• Large anomalous Hall effect in ferromagnetic insulator-topological insulator heterostructures
• Spin chirality fluctuation in two-dimensional ferromagnets with perpendicular anisotropy
• Perpendicular magnetic anisotropy and spin glass-like behavior in molecular beam epitaxy grown chromium telluride thin films
• ZrTe2/CrTe2: an epitaxial van der Waals platform for spintronics
• Mixed topological semimetals driven by orbital complexity in two-dimensional ferromagnets
• Strain-tunable Berry curvature in quasi-two-dimensional chromium telluride
• Sensing the local magnetic environment through optically active defects in a layered magnetic semiconductor
• The range of non-Kitaev terms and fractional particles in RuCl${}_3$
• From Stoner to Local Moment Magnetism in Atomically Thin Cr2Te3
• Self-consistent theory of ferromagnetism on the surface of a topological insulator
• Progress and prospects in the quantum anomalous Hall effect
• Low vibration high numerical aperture automated variable temperature Raman microscope

Cited by in corpus (3)

• Interface-Induced Stability of Nontrivial Topological Spin Textures: Unveiling Room-Temperature Hopfions and Skyrmions
• Enhancement of Curie Temperature in Ferromagnetic Insulator-Topological Insulator Heterostructures
• Competing magnetic phases in Cr${}_{3+\delta }$Te${}_4$ are spatially segregated