Magnetic order of spin S = 1 antiferromagnetic quantum Heisenberg systems on a Bravais lattice: exact local constraint

41st Vietnam National Conference on Theoretical Physics

Nga, Pham Thi Thanh^1 ; Thang, Nguyen Toan^2

Thuyloi University, 175 Tay Son, Dong Da, Hanoi, Viet Nam^1

Institute of Physics, 10 Dao Tan, Ba Dinh, Hanoi, Viet Nam^2

关键词: Antiferromagnetics;    Bravais lattices;    Heisenberg system;    Lattice structures;    Local constraints;    Local coordinate system;    Sublattice magnetization;    Thermodynamical quantities;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/865/1/012015/pdf
DOI  :  10.1088/1742-6596/865/1/012015

来源: IOP

【 摘 要 】

We apply the Popov-Fedotov formalism for investigating magnetic properties of the spin S = 1 Heisenberg antiferomagnetic (HAF) on a Bravais lattice. Mapping spin-1 lattice systems on three-component auxiliary fermions with imaginary chemical potential and transforming to a local coordinate system allow us to express a sublattice magnetization, free energy and other thermodynamical quantities in unique forms for different lattice structures in various magnetically ordered phases. We compare them with the results obtained when the local constraint is disregarded. A comparison with the case of S = 1/2 is also discussed.