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Frustrated Heisenberg antiferromagnet on a pyrochlore lattice

Akihisa Koga·Norio Kawakami
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Abstract

We investigate quantum phase transitions for the $s=1/2$ antiferromagnetic Heisenberg model on a pyrochlore lattice. By means of a series expansion starting from isolated tetrahedra, the ground-state phase diagram is determined. When the ratio of the two competing exchange couplings is varied, the first-order (second-order) quantum phase transition occurs between the two spin gap phases (the spin-gap and the antiferromagnetic phases). We also discuss some properties expected for the s=1 pyrochlore spin system.

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Akihisa Koga, Norio Kawakami. 2000-10-09. Frustrated Heisenberg antiferromagnet on a pyrochlore lattice. https://doi.org/10.1103/physrevb.63.144432

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