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arXiv · 1107.5440

Cubic and non-cubic multiple-q states in the Heisenberg antiferromagnet on the pyrochlore lattice

Tsuyoshi Okubo·Trung Hai Nguyen·Hikaru Kawamura
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Abstract

The ordering of the classical Heisenberg model on the pyrochlore lattice with the antiferromagnetic nearest-neighbor interaction J1 and the ferromagnetic next-nearest-neighbour interaction J2 is investigated by means of a mean-field analysis and a Monte Carlo simulation. For a moderate J2/J1-value, the model exhibits a first-order transition into an incommensurate multiple-q ordered state where multiple Bragg peaks coexist in the spin structure factor. We show that there are two types of metastable multiple-q states, a cubic symmetric sextuple-q state and a non-cubic symmetric quadruple-q state. Based on a Monte Carlo simulation, we find that the cubic sextuple-q state appears just below the first-order transition temperature, while another transition from the cubic sextuple-q state to the non-cubic quadruple-q state occurs at a lower temperature.

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Tsuyoshi Okubo, Trung Hai Nguyen, Hikaru Kawamura. 2011-07-27. Cubic and non-cubic multiple-q states in the Heisenberg antiferromagnet on the pyrochlore lattice. https://doi.org/10.1103/physrevb.84.144432

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