Readout scheme for solid-state nuclear clock

Projektinformationen

CRYSTALCLOCK

ID Finanzhilfevereinbarung: 882708

DOI

10.3030/882708

Projekt abgeschlossen

EK-Unterschriftsdatum 25 Februar 2020

Startdatum 1 April 2020

Enddatum 31 März 2022

Finanziert unter

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Gesamtkosten

€ 186 167,04

EU-Beitrag

€ 186 167,04

Koordiniert durch

TECHNISCHE UNIVERSITAET WIEN
Austria

Periodic Reporting for period 1 - CRYSTALCLOCK (Readout scheme for solid-state nuclear clock)

Berichtszeitraum: 2020-04-01 bis 2022-03-31

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

Time measurement is a technological and commercial need. And for that, people build clocks. Improvement in time measurement goes hand in hand with technological advancements. That is because the accurately measured time can be related to other measurements, distance, gravitational field, and fundamental constants. The nuclear clock will be the next step in improving the technology for accurate measurements and metrology.

The CRYSTALCLOCK project is developing a readout scheme for the Thorium nuclear clock. The readout scheme is based on nuclear quadrupole resonance spectroscopy, (NQRS). The spectroscopy will decipher the microscopic structure of the Thorium atoms in a host crystal.

While conventional atomic clocks rely on the 3-level interrogation scheme where the clock transition is linked to a fast transition that serves for readout. Thorium nuclear clock provides only two accessible nuclear levels. Integrating Thorium ions into a solid-state ionic crystal introduces additional energy levels that will allow for readout using radiofrequency spectroscopy-nuclear quadrupole resonance.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

We have successfully grown Thorium, Neptunium, and Uranium doped CaF2 crystals. We are developing an SRR-based spectrometer for NQR spectroscopy. The motivation behind the SRR spectrometer is to have a compact device capable of detecting nuclear resonances in quadrupolar nuclei. This will have applications beyond the nuclear clock.

We have not detected the frequency of the NQR transition yet. However, the work is in progress. The COVID pandemic has delayed many tasks. Meanwhile, we have confirmed the project's feasibility by measuring the electric field gradient on Neptunium in Np:CaF2 using Mossbauer spectroscopy. The measured values are consistent with theoretical predictions from density functional theory (DFT) calculations. We expect to see the NQR transition before the end of the year 2022.

The preliminary results of the Thorium Nuclear Clock Project were presented at the international Thorium conference “Thorium Nuclear Clock Project Workshop” in Berlin, on 6th May 2022. During the period of the project, the team also published a review paper in a prestigious journal in order to spread ideas about the nuclear clock. The project has made great progress. The preliminary results are very encouraging and show that a nuclear clock is a viable option for keeping time. The team is continuing to work on the project and is hopeful that the nuclear clock will be ready for use in the near future.


Beeks, K., Sikorsky, T., Schumm, T., Thielking, J., Okhapkin, M. V., & Peik, E. (2021). The thorium-229 low-energy isomer and the nuclear clock. Nature Reviews Physics, 3(4), 238-248.


RAW data for all NQR and related experiments are kept at ZENODO repository: https://zenodo.org/record/3931904#.YqsKd3VBzmE

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

While growing the crystals for the NQR experiment, we have developed a method to heal the fluoride deficiency that is inherently present in synthetic and natural fluoride crystals. Fluoride deficiency is a common problem for vacuum ultraviolet optics. The publication of this fluorination technique is already in preparation.

The SRR spectrometer is a highly versatile and compact spectrometer that can be used for a variety of applications where nuclear quadrupole resonance spectroscopy is used. Some of the potential applications for the SRR spectrometer include landmine detection, drug detection, medicine authentication, and oil drilling. The SRR spectrometer's portability and battery-powered operation make it an ideal tool for use in a variety of settings. We are already in contact with the TU Wien patent office. We will file the patent as soon as the device is fully functional. We are confident that our device will be a valuable addition to the market, and we are committed to protecting our intellectual property.

NQR laboratory

PCB board of the SRR spectrometer

Uranium doped single CaF2 crystal.