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arXiv · 1710.00712

Magnetic phase transitions and unusual antiferromagnetic states in the Hubbard model

M. A. Timirgazin·P. A. Igoshev·A. K. Arzhnikov·V. Yu. Irkhin
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Abstract

Ground state magnetic phase diagrams of the square and simple cubic lattices are investigated for the narrow band Hubbard model within the slave-boson approach by Kotliar and Ruckenstein. The transitions between saturated (half-metallic) and non-saturated ferromagnetic phases as well as similar transition in antiferromagnetic (AFM) state are considered in the three-dimensional case. Two types of saturated antiferromagnetic state with different concentration dependences of sublattice magnetization are found in the two-dimensional case in the vicinity of half-filling: the state with a gap between AFM subbands and AFM state with large electron mass. The latter state is hidden by the phase separation in the finite-U case.

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M. A. Timirgazin, P. A. Igoshev, A. K. Arzhnikov, V. Yu. Irkhin. 2017-10-02. Magnetic phase transitions and unusual antiferromagnetic states in the Hubbard model. https://doi.org/10.1016/j.jmmm.2017.10.007

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