Emergent symmetry and dimensional reduction at a quantum critical point

TitleEmergent symmetry and dimensional reduction at a quantum critical point
Publication TypeJournal Article
Year of Publication2008
AuthorsSchmalian J, Batista CD
Journal TitlePhysical Review B
Date PublishedMar
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000254542500086
KeywordsANTIFERROMAGNETS, DISORDER, magnetic-field, systems, temperature

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 BaCuSi2O6.

Alternate JournalPhys. Rev. B