Neel order in the Hubbard model within spin-charge rotating reference frame approach: crossover from weak to strong coupling - Condensed Matter > Strongly Correlated ElectronsReport as inadecuate




Neel order in the Hubbard model within spin-charge rotating reference frame approach: crossover from weak to strong coupling - Condensed Matter > Strongly Correlated Electrons - Download this document for free, or read online. Document in PDF available to download.

Abstract: The antiferromagnetic phase of two-dimensional 2D and three-dimensional3D Hubbard model with nearest neighbors hopping is studied on a bipartitecubic lattice by means of the quantum SU2xU1 rotor approach that yields afully self-consistent treatment of the antiferromagnetic state that respectsthe symmetry properties the model and satisfy the Mermin-Wagner theorem. Thecollective variables for charge and spin are isolated in the form of thespace-time fluctuating U1 phase field and rotating spin quantization axisgoverned by the SU2 symmetry, respectively. As a result interacting electronsappear as a composite objects consisting of bare fermions with attached U1and SU2 gauge fields. An effective action consisting of a spin-charge rotorand a fermionic fields is derived as a function of the Coulomb repulsion U andhopping parameter t. At zero temperature, our theory describes the evolutionfrom a Slater U<>t antiferromagnet. The resultsfor zero-temperature sublatice magnetization 2D and finite temperature 3Dphase diagram of the antiferromagnetic Hubbard model as a function of thecrossover parameter U-t are presented and the role of the spin Berry phase inthe interaction driven crossover is analyzed.



Author: T. A. Zaleski, T. K. Kopec

Source: https://arxiv.org/



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