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arXiv · 2201.04258

Magnetic phase transition in disordered interacting Dirac fermion systems via the Zeeman field

Jingyao Meng·Lufeng Zhang·Tianxing Ma·Hai-Qing Lin
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Abstract

Using the determinant quantum Monte Carlo method, we investigate the antiferromagnetic phase transition that is induced by the Zeeman field in a disordered interacting two-dimensional Dirac fermion system. At a fixed interaction strength $U$, the antiferromagnetic correlation is enhanced as the magnetic filed increases, and when the magnetic field is larger than a $B_{c}(U)$, the antiferromagnetic correlation shall be suppressed by the increased magnetic field. The impact of Zeeman field $B$, Coulomb repulsion $U$ and disorder $\Delta$ is not isolated. The intensity of magnetic field effect on the antiferromagnetic correlation shall be strongly suppressed by disorder. Differently, it will be promoted by weak interaction, but when $U$ becomes larger than $U_{c}=4.5$, the increased interaction will suppress the intensity of this effect, and here $U_{c}=4.5$ coincides with the critical strength inducing the metal-Mott insulator transition in clean system. Moreover, at a fixed magnetic field $B$, strong interaction shall suppress the antiferromagnetic phase rather than promote it.

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Jingyao Meng, Lufeng Zhang, Tianxing Ma, Hai-Qing Lin. 2022-01-12. Magnetic phase transition in disordered interacting Dirac fermion systems via the Zeeman field. https://doi.org/10.1103/physrevb.105.205121

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