Project description
Probing highly charged and very compact ions for dark matter insight
When one or more electrons are removed from an atom, the remaining ones are pulled more tightly towards the nucleus. Highly charged ions (HCIs) are an extreme case where the valence electrons are bound orders of magnitude more tightly than usual, making them less vulnerable to outside influence and potentially valuable for high-precision atomic clocks and quantum information applications. They are also excellent systems to study the fundamental physics of atomic systems under such extreme conditions and to probe for physics beyond the Standard Model. The EU-funded FunClocks project will perform high-precision optical clock spectroscopy on HCIs that could reveal new physics and deepen our understanding of dark matter.
Objective
Precision spectroscopy of highly charged ions (HCI) provides insight into atomic systems in which electrons are highly correlated, strongly relativistic, and experience strong internal fields. Thus, HCI are excellent systems to probe and refine our understanding of physics under these extreme conditions. They are the most sensitive known atomic species to probe for possible changes in fundamental constants and offer advantageous properties to study coupling of hypothetical dark matter fields to normal matter. For these applications, high-precision optical spectroscopy of HCI is required. In the past, the spectroscopic resolution of optical transitions in HCI was limited by Doppler-broadening to hundreds of megahertz. We have recently demonstrated the first hertz-level laser spectroscopy of an optical fine-structure transition in highly charged argon using sympathetic cooling and quantum logic with a co-trapped logic ion in a Paul trap, improving the spectroscopic precision by nine orders of magnitude compared to the previous state-of-the-art. Here, we propose to further develop quantum techniques for controlling HCI and to push spectroscopic resolution in order to realise next generation optical clocks based on promising reference transitions in HCI. We will employ these novel types of optical clocks to advance our understanding of atomic structure and to probe for physics beyond the standard model. Sub hertz-level isotope shift spectroscopy of highly charged calcium ions will be performed to improve current bounds on hypothetical fifth forces that couple neutrons and electrons. Furthermore, we will perform optical clock-type spectroscopy on HCI that offer up to a 20-fold higher sensitivity to a possible change in the fine-structure constant and a non-gravitational coupling between dark matter and normal matter than existing clocks. Through frequency comparisons with other clocks, we will improve bounds on these new physics effects.
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ERC-ADG - Advanced GrantHost institution
38116 Braunschweig
Germany