Direct Probing of the Mott Crossover in the SU(N) Fermi-Hubbard Model

Hofrichter, Christian; Riegger, Luis; Scazza, Francesco; Höfer, Moritz; Fernandes, Diogo Rio; Bloch, Immanuel und Fölling, Simon (2016): Direct Probing of the Mott Crossover in the SU(N) Fermi-Hubbard Model. In: Physical Review X, Vol. 6, No. 2, 021030

Abstract

We report on a detailed experimental investigation of the equation of state (EoS) of the three-dimensional Fermi-Hubbard model (FHM) in its generalized SU(N)-symmetric form, using a degenerate ytterbium gas in an optical lattice. In its more common spin-1/2 form, the FHM is a central model of condensed-matter physics. The generalization to N > 2 was first used to describe multi-orbital materials and is expected to exhibit novel many-body phases in a complex phase diagram. By realizing and locally probing the SU(N) FHM with ultracold atoms, we obtain model-free access to thermodynamic quantities. The measurement of the EoS and the local compressibility allows us to characterize the crossover from a compressible metal to an incompressible Mott insulator. We reach specific entropies above Neel order but below that of uncorrelated spins. Having access to the EoS of such a system represents an important step towards probing predicted novel SU(N) phases.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 2160-3308
• Language: English