Physics of higher orbital bands in optical lattices: a review

TL;DR

This review discusses how higher orbital bands in optical lattices enable the simulation of exotic quantum phases, revealing new many-body states and topological phenomena beyond traditional solid-state systems.

Contribution

It provides a comprehensive overview of orbital degrees of freedom in optical lattices, summarizing models, phases, and experimental implications of higher orbital physics.

Findings

High orbitals facilitate the realization of complex Bose-Einstein condensates.

Orbital degrees of freedom lead to topological semimetals in optical lattices.

Experimental techniques enable exploration of exotic many-body states.

Abstract

Orbital degree of freedom plays a fundamental role in understanding the unconventional properties in solid state materials. Experimental progress in quantum atomic gases has demonstrated that high orbitals in optical lattices can be used to construct quantum emulators of exotic models beyond natural crystals, where novel many-body states such as complex Bose-Einstein condensation and topological semimetals emerge. A brief introduction of orbital degree of freedom in optical lattices is given and a summary of exotic orbital models and resulting many-body phases is provided. Experimental consequences of the novel phases are also discussed.