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arXiv:2210.07300 · Physical review. B./Physical review. B

Phase diagram of mixed-dimensional anisotropic t−J models

Julius Dicke, Lukas Rammelmüller, Fabian Grusdt, Lode Pollet

Published Feb 6, 2023• 2 citations
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Abstract

We study the phase diagram of two different mixed-dimensional $t\text{\ensuremath{-}}{J}_{z}\text{\ensuremath{-}}{J}_{\ensuremath{\perp}}$ models on the square lattice, in which the hopping amplitude $t$ is only nonzero along the $x$ direction. In the first model, which is bosonic, the spin-exchange amplitude ${J}_{\ensuremath{\perp}}$ is negative and isotropic along the $x$ and $y$ directions of the lattice, and ${J}_{z}$ is isotropic and positive. The low-energy physics is characterized by spin-charge separation: the holes hop as free fermions in an easy-plane ferromagnetic background. In the second model, ${J}_{\ensuremath{\perp}}$ is restricted to the $x$ axis while ${J}_{z}$ remains isotropic and positive. The model is agnostic to particle statistics, and shows stripe patterns with antiferromagnetic N\'eel order at low temperature and high hole densities, in resemblance of the mixed-dimensional $t\text{\ensuremath{-}}{J}_{z}$ and $t\text{\ensuremath{-}}J$ models. At lower hole density, a very strong first-order transition and hysteresis loop is seen extending to a remarkably high 14(1)% hole doping.

DOI
10.1103/physrevb.107.075109

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