Discriminating antiferromagnetic signatures in ultracold fermions by tunable geometric frustration

Autor:	Chang, Chia-Chen, Scalettar, Richard T., Gorelik, Elena V., Blümer, Nils
Rok vydání:	2013
Předmět:	Condensed Matter - Quantum Gases Condensed Matter - Strongly Correlated Electrons
Zdroj:	Phys. Rev. B 88, 195121 (2013)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevB.88.195121
Popis:	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 determinant quantum Monte Carlo 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 $s\lesssim \ln(2)$ (and restores Pomeranchuk cooling at strong frustration), paving the way to the long-sought experimental detection of antiferromagnetism in ultracold fermions on optical lattices. Comment: 5 pages
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1306.4687 Zobrazit plný text záznamu View this record from Arxiv