Direct probing of the Mott crossover in the SU($N$) Fermi-Hubbard model

TL;DR

This paper experimentally investigates the SU(N)-symmetric Fermi-Hubbard model using ultracold ytterbium gases, providing insights into the Mott crossover and paving the way for exploring novel magnetic phases.

Contribution

It presents the first detailed experimental probing of the SU(N)-symmetric Fermi-Hubbard model across different interaction regimes using local measurements.

Findings

Observation of the Mott insulator state in SU(N) systems

Characterization of the Mott crossover in ultracold gases

Preparation of low-temperature SU(N)-symmetric Mott insulators

Abstract

The Fermi-Hubbard model (FHM) is a cornerstone of modern condensed matter theory. Developed for interacting electrons in solids, which typically exhibit SU($2$) symmetry, it describes a wide range of phenomena, such as metal to insulator transitions and magnetic order. Its generalized SU($N$)-symmetric form, originally applied to multi-orbital materials such as transition-metal oxides, has recently attracted much interest owing to the availability of ultracold SU($N$)-symmetric atomic gases. Here we report on a detailed experimental investigation of the SU($N$)-symmetric FHM using local probing of an atomic gas of ytterbium in an optical lattice to determine the equation of state through different interaction regimes. We prepare a low-temperature SU($N$)-symmetric Mott insulator and characterize the Mott crossover, representing important steps towards probing predicted novel SU($N$)-magnetic phases.