A long-lived spin-orbit-coupled degenerate dipolar Fermi gas

TL;DR

This paper reports the creation of a long-lived, spin-orbit-coupled degenerate Fermi gas of dysprosium atoms, demonstrating extended lifetimes and observable dipolar interactions, enabling future studies of complex quantum many-body phenomena.

Contribution

It introduces a novel long-lived spin-orbit-coupled fermionic gas using dysprosium, surpassing previous alkali-metal systems in lifetime and revealing dipolar effects in the system.

Findings

Lifetimes up to 400 ms, ten to hundred times longer than alkali gases.

Observation of dipolar interactions affecting spin dynamics.

Suppressed dipolar relaxation at high magnetic fields.

Abstract

We describe the creation of a long-lived spin-orbit-coupled gas of quantum degenerate atoms using the most magnetic fermionic element, dysprosium. Spin-orbit-coupling arises from a synthetic gauge field created by the adiabatic following of degenerate dressed states comprised of optically coupled components of an atomic spin. Because of dysprosium's large electronic orbital angular momentum and large magnetic moment, the lifetime of the gas is limited not by spontaneous emission from the light-matter coupling, as for gases of alkali-metal atoms, but by dipolar relaxation of the spin. This relaxation is suppressed at large magnetic fields due to Fermi statistics. We observe lifetimes up to 400 ms, which exceeds that of spin-orbit-coupled fermionic alkali atoms by a factor of 10-100, and is close to the value obtained from a theoretical model. Elastic dipolar interactions are also observed to influence the Rabi evolution of the spin, revealing an interacting fermionic system. The long lifetime of this weakly interacting spin-orbit-coupled degenerate Fermi gas will facilitate the study of quantum many-body phenomena manifest at longer timescales, with exciting implications for the exploration of exotic topological quantum liquids.