Discriminating antiferromagnetic signatures in systems of ultracold fermions by tunable geometric frustration

Article

关键词: MODEL SPIN CORRELATIONS;    OPTICAL LATTICE;    ISING-MODEL;    TRIANGULAR LATTICE;    QUANTUM SIMULATION;    SIGN PROBLEM;    ATOMS;    MAGNETISM;   

DOI  :  10.1103/PhysRevB.88.195121

来源: SCIE

【 摘 要 】

Recently, it has become possible to tune optical lattices continuously between square and triangular geometries. We compute thermodynamics and spin correlations in the corresponding Hubbard model using a determinant quantum Monte Carlo technique and show that the frustration effects induced by the variable hopping terms can be clearly separated from concomitant bandwidth changes by a proper rescaling of the interaction. An enhancement of the double occupancy by geometric frustration signals the destruction of nontrivial antiferromagnetic correlations at weak coupling and entropy s <= ln(2) (and restores Pomeranchuk cooling at strong frustration), paving the way to the long-sought experimental detection of antiferromagnetism in ultracold fermions on optical lattices.

【 授权许可】

Free