Progress in the development of the <sup>229</sup>Th solid-state nuclear clock

POSTER

Abstract

Unique among nuclear excited states, the 229mTh nuclear isomeric state is addressable by current table-top vacuum-ultraviolet (VUV) laser technology [1]. As such, it can serve as the platform of an optical nuclear clock of incredibly high precision and accuracy,  capable of probing the variability of the fundamental constants [2]. Moreover, it is possible to realize the nuclear clock in different solid-state architectures and host materials [3–5]. Significant effort has been made in characterizing the decay channels in these materials, including recent advances in both radiative decay via photon emission and conversion electron Mössbauer spectroscopy (CEMS) [6–9]

We will report on our progress to understand behavior of the isomer in different solid-state environments, including our study of different host materials and recent CEMS studies in ThO2. We will also report on our progress to generate (VUV) light via four-wave mixing in Cadmium.  

[1] Elwell, R. et al. Laser Excitation of the 229Th nuclear isomeric transition in a solid-state host. Phys. Rev. Lett. 133, 013201 (2024)

[2] Rellergert, W. et al. Constraining the Evolution of the Fundamental Constants with a Solid-State Optical Frequency Reference Based on the 229Th Nucleus. Phys. Rev. Lett. 104, 200802 (2010)

[3] Zhang, C. et al. 229ThF4 thin films for solid-state nuclear clocks. Nature 636, 603 (2024)

[4] Pineda, S.V. et. al. Radiative decay of the 229mTh nuclear clock isomer in different host materials. Phys. Rev. Res. 7, 013052 (2025)

[5] Morgan, H.W.T. et. al. Proposal and theoretical investigation of 229Th-doped nonlinear optical crystals for compact solid-state clocks. Applied Physics Letters 126, 111101 (2025)

[6] Perera, U.C. et. al. Host-dependent frequency offsets in 229Th nuclear clockwork. Phys. Rev. Lett. 135, 123001 (2025)

[7] Elwell, R. et. al. Laser-Based Conversion Electron Mossbauer Spectroscopy of 229ThO2. Nature 648, 300 (2025)

[8] Terhune, J. et al. Photoinduced quenching of the 229Th isomer in a solid-state host. Phys. Rev. Research 7, L022062 (2025)

[9] Morgan, H.W.T. et. al. Theory of Internal Conversion of the 229Th Nuclear Isomer in Solid-State Hosts. Phys. Rev. Lett. 134, 253801 (2025)

Presenters

  • Albert Bao

    • University of California, Los Angeles

Authors

  • Albert Bao

    • University of California, Los Angeles
  • James Terhune

    • University of California, Los Angeles
  • Ricky Elwell

    • University of California, Los Angeles
  • Alexandros Androutsos

    • University of California, Los Angeles
  • Anastassia Alexandrova

    • UCLA
    • University of California, Los Angeles
  • David Shao

    • University of California, Los Angeles
  • Andrei P Derevianko

    • University of Nevada, Reno
  • Hoang Bao Tran Tan

    • University of Nevada, Reno
  • Udeshika Chathurangani Perera

    • Mississippi State University
    • University of Nevada, Reno
  • Nico Vagner

    • University of Nevada, Reno
  • R. Jason Jones

    • University of Arizona
  • Yushi Kaneda

    • University of Arizona
  • John McCauley

    • University of Arizona
  • Dylan P Tooley

    • University of Arizona
  • Tyrel M McQueen

    • Johns Hopkins University
  • Allana Iwanicki

    • John Hopkins University
  • Andrew Merriam

    • Lumeras
  • Harry Morgan

    • University of Manchester
  • Eric R. Hudson

    • University of California, Los Angeles