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Unveiling Order behind Complexity: Coexistence of Ferromagnetism and Bose-Einstein Condensation

C. D. Batista·G. Ortiz·J. E. Gubernatis
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Abstract

We present an algebraic framework for identifying the order parameter and the possible phases of quantum systems that is based on identifying the local dimension $N$ of the quantum operators and using the SU(N) group representing the generators of generalized spin-particle mappings. We illustrate this for $N$=3 by presenting for any spatial dimension the exact solution of the bilinear-biquadratic $S$=1 quantum Heisenberg model at a high symmetry point. Through this solution we rigorously show that itinerant ferromagnetism and Bose-Einstein condensation may coexist.

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C. D. Batista, G. Ortiz, J. E. Gubernatis. 2002-07-02. Unveiling Order behind Complexity: Coexistence of Ferromagnetism and Bose-Einstein Condensation. https://doi.org/10.1103/physrevb.65.180402

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