Thorium-229 and the nuclear clock: Current developments and perspectives as a novel quantum sensor
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The radioisotope thorium-229 features a low-energy isomer with an exceptional excitation energy of only about 8 eV above the ground state. This state, unique across the presently known nuclear chart, has attracted the attention of physicists since more than 4 decades as it has been proposed to serve as the basis for a new generation of timekeeping instruments: the nuclear clock. Such a device could serve as a next-generation highly sensitive quantum sensor for a plethora of fundamental physics applications, including the search for time-variations of fundamental constants or (ultra-light) dark matter candidates.
Since the first direct evidence for this low-energy nuclear excitation has been found in 2016, significant progress has been made on the characterization of this unique nuclear state, in which CERN’s ISOLDE facility played a significant role when recently the first identification of the radiative de-excitation of the thorium isomer could be achieved. In this presentation, the concept and potential applications of an optical nuclear clock will be reviewed and the current state of knowledge and perspectives of experimental activities are discussed.
Refreshments will be served at 10:30.
Jan Fiete Grosse-Oetringhaus and Pedro Silva