6533b7d6fe1ef96bd1266816
RESEARCH PRODUCT
Universal probes for antiferromagnetic correlations and entropy in cold fermions on optical lattices
Richard T. ScalettarN. BlümerAndreas KlümperThereza PaivaE. V. GorelikDaniel Rostsubject
PhysicsStrongly Correlated Electrons (cond-mat.str-el)Hubbard modelCondensed matter physicsExchange interactionFOS: Physical sciencesFermionApproxKinetic energyAtomic and Molecular Physics and OpticsCondensed Matter - Strongly Correlated ElectronsQuantum Gases (cond-mat.quant-gas)Lattice (order)AntiferromagnetismCondensed Matter::Strongly Correlated ElectronsCondensed Matter - Quantum GasesEntropy (order and disorder)description
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=S/(N k_B)=s*=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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-01-26 |