Readout scheme for the solid-state 229Th nuclear clock

01.07.2020 - 30.06.2023

The low‐energy excited state of the Thorium‐229 (229Th) nucleus has fascinated researchers for decades. With the excitation energy of only a few eV, it is the only known nuclear isomeric state accessible to laser manipulation. This system opens up a plethora of novel applications, ranging from tests on temporal variations of the fundamental interaction constants to technological implementations as an ultra‐precise “optical nuclear clock”. While the exact excitation energy of the 229Th isomer remains elusive, significant progress has been made in constraining its energy in recent months. All recent results place the energy between 8.0 eV to 8.5 eV. This is within the transmission band of large‐band‐gap VUV materials such as single fluoride crystals. It becomes hence possible to embed 229Th inside a solid‐state matrix and address a large number of nuclei optically. This project aims to develop a readout scheme for a solid‐state nuclear clock based on nuclear quadrupole resonance spectroscopy (NQRS). The interaction of the nuclear quadrupole moment with the electric field gradient of the crystal causes the splitting of the nuclear states. NQRS can be used for non‐destructive readout of the nuclear state during clock operation. Moreover, the NQRS will provide valuable information about the microscopic structure of 229Th atoms doped into the crystal lattice. NQRClock project will be conducted at the Thorsten Schumm's quantum metrology research group by Tomas Sikorsky. He will be supported by other members of the group. Moreover, the research group of Hermann Scharfetter will perform pilot NQR measurements. Theoretical parts will be conducted by Andreas Grüneis, Adriana Palffy, and Cesare Francini.





  • Fonds zur Förderung der wissenschaftlichen Forschung (FWF) (National) Einzelprojekt Fonds zur Förderung der wissenschaftlichen Forschung (FWF) Fördergeber Typ Forschungsförderungsinstitutionen Ausschreibungskennung P 33627


  • Quantum Physics and Quantum Technologies

Externe Partner_innen

  • Institut für Medizintechnik