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arXiv · 0710.1376

Emergent Symmetry and Dimensional Reduction at a Quantum Critical Point

J. Schmalian·C. D. Batista
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Abstract

We show that the spatial dimensionality of the quantum critical point associated with Bose--Einstein condensation at T=0 is reduced when the underlying lattice comprises a set of layers coupled by a frustrating interaction. For this purpose, we use an heuristic mean field approach that is complemented and justified by a more rigorous renormalization group analysis. Due to the presence of an emergent symmetry, i.e. a symmetry of the ground state that is absent in the underlying Hamiltonian, a three--dimensional interacting Bose system undergoes a chemical potential tuned quantum phase transition that is strictly two dimensional. Our theoretical predictions for the critical temperature as a function of the chemical potential correspond very well with recent measurements in BaCuSi$_{2}$O$_{6}$.

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J. Schmalian, C. D. Batista. 2007-10-22. Emergent Symmetry and Dimensional Reduction at a Quantum Critical Point. https://doi.org/10.1103/physrevb.77.094406

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