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arXiv · 1204.3824

Effective approach to the Nagaoka regime of the two dimensional t-J model

M. M. Maska·M. Mierzejewski·E. A. Kochetov·L. Vidmar·J. Bonca·O. P. Sushkov
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Abstract

We argue that the t-J model and the recently proposed Ising version of this model give the same physical picture of the Nagaoka regime for J/t << 1. In particular, both models are shown to give compatible results for a single Nagaoka polaron as well as for a Nagaoka bipolaron. When compared to the standard t-J or t-Jz models, the Ising version allows for a numerical analysis on much larger clusters by means of classical Monte Carlo simulations. Taking the advantage of this fact, we study the low doping regime of t-J model for J/t << 1 and show that the ground state exhibits phase separation into hole-rich ferromagnetic and hole-depleted antiferromagnetic regions. This picture holds true up to a threshold concentration of holes, \delta < \delta_t ~ 0.44 \sqrt{J/t}. Analytical calculations show that \delta_t=\sqrt{J/2\pi t}.

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M. M. Maska, M. Mierzejewski, E. A. Kochetov, L. Vidmar, J. Bonca, O. P. Sushkov. 2012-04-17. Effective approach to the Nagaoka regime of the two dimensional t-J model. https://doi.org/10.1103/physrevb.85.245113

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