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Updated: Jul 15, 2026
Fabricating van der Waals Heterostructures with Precise Rotational Alignment
Published on: July 5, 2019
Magnetic properties of CDW-TaS2: from itinerant electron-mediated interactions to interlayer coupling mechanisms
Changjie Lian1,2, Jia Wei1, Ping Guo2
1Institute of Photonics & Photon-Technology, Northwest University, Xi'an, Shaanxi 710127, China.
Abstract:
The ground-state magnetic properties of the charge-density wave (CDW) phase of TaS2 have long been a subject of debate. Because the spatial distance between the localized magnetic moments in this system is as large as ∼12 Å, direct exchange interactions are negligible, leaving the microscopic mechanism of its long-range magnetic exchange unresolved. In this work, based on the precise electronic structure obtained from density functional theory (DFT) calculations, and by comprehensively considering the geometric frustration and many-body correlation effects of the triangular lattice, we systematically construct an effective Hamiltonian model for low-energy spin interactions. This model not only reveals the magnetic exchange mediated by itinerant electrons but also quantitatively analyzes the competing relationships among different ground states, including ferromagnetic (FM), antiferromagnetic (AFM), and quantum spin liquid (QSL) states, demonstrating that the FM ground state is robust against quantum fluctuations within a specific parameter regime. Further analysis indicates that the adjacent interlayer AFM coupling in multilayer TaS2 systems is primarily governed by the exchange antisymmetry arising from the direct overlap of the 5dz2 orbitals of the Ta atoms at the centers of the Star-of-David clusters. This study provides systematic theoretical support for understanding the magnetic properties of such strongly correlated CDW electronic systems.
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