Journal of Physics: Conference Series 1932, 012014 (2021)

ISSN: 1742-6596

Spin excitations in the Kitaev-Heisenberg model: Popov-Fedotov fermionization

Pham Thi Thanh Nga, Nguyen Van Hinh and Nguyen Toan Thang

We study a Kitaev-Heisenberg model of spin 1/2 using the Popov-Fedotov fermionization proccedure. We derive the free energy of the quantum spin system on a Bravais lattice within one-loop approximation with exact on- site constraint. We discuss the obtained magnetic excitation spectrum for a particular case of square lattice in relation to the data derived by the equation of motion method and with the result of the linear spin wave theory in Holstein - Primakoff representation.

DOI: 10.1088/1742-6596/1932/1/012014

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