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Frustrated Heisenberg antiferromagnets: fluctuation induced first order vs deconfined quantum criticality

Frank Krüger·Stefan Scheidl
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Abstract

Recently it was argued that quantum phase transitions can be radically different from classical phase transitions with as a highlight the 'deconfined critical points' exhibiting fractionalization of quantum numbers due to Berry phase effects. Such transitions are supposed to occur in frustrated ('$J_1$-$J_2$') quantum magnets. We have developed a novel renormalization approach for such systems which is fully respecting the underlying lattice structure. According to our findings, another profound phenomenon is around the corner: a fluctuation induced (order-out-of-disorder) first order transition. This has to occur for large spin and we conjecture that it is responsible for the weakly first order behavior recently observed in numerical simulations for frustrated $S=1/2$ systems.

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Frank Krüger, Stefan Scheidl. 2006-01-11. Frustrated Heisenberg antiferromagnets: fluctuation induced first order vs deconfined quantum criticality. https://doi.org/10.1209/epl%2Fi2006-10039-3

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