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Quantum phase transitions and dimensional reduction in antiferromagnets with inter-layer frustration

Oliver Rösch·Matthias Vojta
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Abstract

For magnets with a fully frustrated inter-layer interaction, we argue that the quantum phase transitions from a paramagnetic to an antiferromagnetic ground state, driven by pressure or magnetic field, are asymptotically three-dimensional, due to interaction-generated non-frustrated inter-layer couplings. However, the relevant crossover scale is tiny, such that two-dimensional behavior occurs in an experimentally relevant low-temperature regime. In the pressure-driven case the phase transition may split, in which case an Ising symmetry related to inter-layer bond order is broken before magnetism occurs. We discuss the relation of our results to recent experiments on BaCuSi2O6.

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Oliver Rösch, Matthias Vojta. 2007-11-08. Quantum phase transitions and dimensional reduction in antiferromagnets with inter-layer frustration. https://doi.org/10.1103/physrevb.76.180401

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