2012/01/31 by E. V. Gorelik, E.V. Gorelik, D. Rost +7
Physics and Astronomy · #Advanced Condensed Matter Physics #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #cond-mat.quant-gas #cond-mat.str-el
paper · pdf · doi:10.1103/physreva.85.061602
published as Phys. Rev. A 85, 061602(R) (2012) · 4+e pages, 4 figures; this paper significantly expands the strong-coupling scenario put forward in arXiv:1105.3356 (but omits other parts for which arXiv:1105.3356 has already been cited in PRL). Version accepted for publication in Phys. Rev. A RC
arxiv created 2012/06/05 · openalex publication_date 2012/06/07 · arxiv updated 2012/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We determine antiferromagnetic (AF) signatures in the half-filled Hubbard model at strong coupling on a cubic lattice and in lower dimensions. Upon cooling, the transition from the charge-excitation regime to the AF Heisenberg regime is signaled by a universal minimum of the double occupancy at entropy s\ensuremath≡S/(NkB)=s*\ensuremath≈ln(2) per particle and a linear increase of the next-nearest-neighbor (NNN) spin correlation function for s<s*. This crossover, driven by a gain in kinetic exchange energy, appears as the essential AF physics relevant for current cold-atom experiments. The onset of long-range AF order (at low s on cubic lattices) is hardly visible in nearest-neighbor spin correlations versus s, but could be detected in spin correlations at or beyond NNN distances.