Atomic-Layer-Controlled Magnetic Orders in MnBi2Te4-Bi2Te3 Topological Heterostructures
Xiong Yao1,2, Qirui Cui1,3, Zengle Huang4
1Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Nano Letters
|July 30, 2024
Summary
This study explores magnetic orders in MnBi2Te4-Bi2Te3 superlattices. Researchers found that both ferromagnetic and antiferromagnetic orders can be precisely controlled by adjusting layer composition and spacing.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Van der Waals (vdW) heterostructures offer unique platforms for emergent phenomena.
- MnBi2Te4-(Bi2Te3)n is a natural vdW material combining topology and magnetism.
- Understanding and controlling magnetic order is crucial for spintronic applications.
Purpose of the Study:
- To investigate the interplay between structure and magnetic order in MnBi2Te4-Bi2Te3 vdW superlattices.
- To demonstrate methods for independently controlling ferromagnetic (FM) and antiferromagnetic (AFM) orders.
- To elucidate the fundamental origins of FM and AFM ordering in this system.
Main Methods:
- Fabrication of atomically engineered sandwich structures using Bi2Te3 and MnBi2Te4 layers.
- Systematic variation of Mn-Mn interatomic distances.
- Systematic variation of the Bi2Te3/MnBi2Te4 ratio.
Main Results:
- The system exhibits both ferromagnetic (FM) and antiferromagnetic (AFM) orders.
- AFM order is solely determined by the Mn-Mn distance.
- FM order depends exclusively on the overall Bi2Te3/MnBi2Te4 ratio, irrespective of Mn-Mn distance.
- Independent control of FM and AFM orders is achieved by structural engineering.
Conclusions:
- The study provides a clear understanding of the distinct origins of AFM and FM orders in MnBi2Te4-Bi2Te3.
- Atomic-level structural control allows for tunable magnetic properties in vdW heterostructures.
- These findings offer a roadmap for designing and manipulating magnetic orders in magneto-topological materials.
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