This hope has already been fulfilled: “We were able to discover the quantum electrodynamic nuclear recoil, an essential theoretical prediction, in a five-electron system, which has actually not been achieved in any other experiment before.”
Ahead of time, the group had to resolve some essential issues, such as detection and cooling, in years of work: For atomic clocks, one needs to cool the particles down extremely in order to stop them as much as possible and thus read out their frequency at rest. Highly charged ions, nevertheless, are produced by developing an extremely hot plasma. Due to the fact that of their severe atomic structure, highly charged ions cant be cooled directly with laser light, and standard detection approaches cant be used either.
This was solved by a cooperation in between MPIK in Heidelberg and the QUEST Institute at PTB by separating a single highly charged argon ion from a hot plasma and keeping it in an ion trap together with a singly charged beryllium ion. This enables the highly charged ion to be cooled indirectly and studied by methods of the beryllium ion.
An innovative cryogenic trap system was then constructed at MPIK and finalized at PTB for the following experiments, which were carried out in part by students switching between the institutions. Consequently, a quantum algorithm developed at PTB prospered in cooling the extremely charged ion even further, specifically close to the quantum mechanical ground state.
Now the researchers have actually successfully taken the next step: They have recognized an optical atomic clock based on thirteen-fold charged argon ions and compared the ticking with the existing ytterbium ion clock at PTB. To do this, they had to evaluate the system in terrific information in order to understand, for example, the movement of the highly charged ion and the effects of external disturbance fields.
They attained a measurement unpredictability of 2 parts in 1017 − similar to lots of currently run optical atomic clocks. “We expect an additional reduction of the uncertainty through technical improvements, which need to bring us into the variety of the best atomic clocks,” states research group leader Piet Schmidt.
The scientists have therefore created a serious competitor to existing optical atomic clocks based upon, for instance, specific ytterbium ions or neutral strontium atoms. The techniques used are generally appropriate and permit several highly charged ions to be studied.
These include atomic systems that can be used to search for extensions of the Standard Model of particle physics. Other extremely charged ions are particularly delicate to changes in the great structure consistent and to certain dark matter prospects that are required in designs beyond the Standard Model however might not be found with previous approaches.
Referral: “An optical atomic clock based on an extremely charged ion” by Steven A. King, Lukas J. Spieß, Peter Micke, Alexander Wilzewski, Tobias Leopold, Erik Benkler, Richard Lange, Nils Huntemann, Andrey Surzhykov, Vladimir A. Yerokhin, José R. Crespo López-Urrutia and Piet O. Schmidt, 2 November 2022, Nature.DOI: 10.1038/ s41586-022-05245-4.
Illustration of the laser interrogation of a highly charged ion clock (art work). Credit: PTB
The researchers of the QUEST Institute at PTB have established and evaluated a brand-new kind of optical atomic clock.
Extremely charged ions are a kind of matter that is frequently found in the universes, such as in the sun or other stars. They are called “extremely charged” because they have actually lost lots of electrons and therefore have a strong positive charge.
As a result, the outermost electrons in extremely charged ions are more strongly bound to the atomic nucleus than in neutral or weakly charged atoms. This makes highly charged ions less impacted by external electro-magnetic fields, but more conscious the essential impacts of unique relativity, quantum electrodynamics, and the atomic nucleus.
” Therefore, we anticipated that an optical atomic clock with highly charged ions would assist us to better test these essential theories”, discusses Physikalisch-Technische Bundesanstalt (PTB) physicist Lukas Spieß.
In advance, the team had to fix some fundamental problems, such as detection and cooling, in years of work: For atomic clocks, one has to cool the particles down exceptionally in order to stop them as much as possible and hence read out their frequency at rest. Extremely charged ions, however, are produced by producing an extremely hot plasma. Due to the fact that of their extreme atomic structure, extremely charged ions cant be cooled straight with laser light, and basic detection techniques cant be utilized either.
An advanced cryogenic trap system was then constructed at MPIK and settled at PTB for the following experiments, which were brought out in part by trainees changing between the organizations. Consequently, a quantum algorithm developed at PTB succeeded in cooling the highly charged ion even further, namely close to the quantum mechanical ground state.
