Collective excitations of dipolar gases based on local tunneling in superlattices

TL;DR

This paper investigates the collective quantum dynamics of dipolar fermionic gases in a one-dimensional superlattice, revealing phonon-like excitations driven by local tunneling influenced by dipolar interactions.

Contribution

It introduces a new type of collective dynamics based on local tunneling in dipolar gases within superlattices, supported by ab-initio simulations and analytical modeling.

Findings

Discovery of phonon-like dispersion relations in the system

Identification of pure quantum tunneling effects without classical analogs

Demonstration of collective transport mediated by dipolar interactions

Abstract

The collective dynamics of a dipolar fermionic quantum gas confined in a one-dimensional double-well superlattice is explored. The fermionic gas resides in a paramagnetic-like ground state in the weak interaction regime, upon which a new type of collective dynamics is found when applying a local perturbation. This dynamics is composed of the local tunneling of fermions in separate supercells, and is a pure quantum effect, with no classical counterpart. Due to the presence of the dipolar interactions the local tunneling transports through the entire superlattice, giving rise to a collective dynamics. A well-defined momentum-energy dispersion relation is identified in the ab-initio simulations demonstrating the phonon-like behavior. The phonon-like characteristic is also confirmed by an analytical description of the dynamics within a semiclassical picture.