Nuclear clocks based on resonant excitation of gamma-transitions

TL;DR

This paper reviews the concept of nuclear clocks based on gamma-transition resonant excitation, highlighting their potential advantages and current experimental efforts focusing on the Th-229 isomeric transition.

Contribution

It introduces the idea of nuclear clocks using gamma-transitions and summarizes recent experimental progress on the Th-229 isomeric transition for optical observation.

Findings

Experimental efforts on Th-229 transition are ongoing.

Nuclear clocks could offer high stability and insensitivity to systematic shifts.

Plans for high-resolution laser spectroscopy are outlined.

Abstract

We review the ideas and concepts for a clock that is based on a radiative transition in the nucleus rather than in the electron shell. This type of clock offers advantages like an insensitivity against field-induced systematic frequency shifts and the opportunity to obtain high stability from interrogating many nuclei in the solid state. Experimental work concentrates on the low-energy (about 8 eV) isomeric transition in Th-229. We review the status of the experiments that aim at a direct optical observation of this transition and outline the plans for high-resolution laser spectroscopy experiments.