Research / 01 / selected publications

Thorium-229 nuclear clock

Building clocks around a uniquely low-energy nuclear transition to test fundamental physics and create robust new frequency standards.

2026

Nuclear clock

Defect assignment of the clock site in ²²⁹Th:CaF₂

D. A. Rhen, H. W. T. Morgan, H. E. Mason, H. B. Tran Tan, R. Elwell, et al.

arXiv:2607.12202

Open paper

Nuclear clock

Ab initio calculations of ²²⁹Th band-to-band internal conversion rate in ²²⁹ThO₂

U. C. Perera, H. B. Tran Tan, H. W. T. Morgan, E. R. Hudson, D. A. Rhen, and A. Derevianko

arXiv:2607.08941

Open paper

Review

Colloquium: Nuclear Clocks

A. Derevianko, R. T. Elwell, and E. R. Hudson

arXiv:2606.11048

Open paper

2025

Nuclear clock

Laser-based conversion electron Mössbauer spectroscopy of ²²⁹ThO₂

R. Elwell, J. E. S. Terhune, C. Schneider, H. W. T. Morgan, et al.

Nature 648, 300

Open paper

Nuclear clock

Host-dependent frequency offsets in ²²⁹Th nuclear clockwork

U. C. Perera, H. W. T. Morgan, E. R. Hudson, and A. Derevianko

Physical Review Letters 135, 123001

Open paper

Nuclear clock

Theory of Internal Conversion of the ²²⁹Th Nuclear Isomer in Solid-State Hosts

H. W. T. Morgan, H. B. Tran Tan, R. Elwell, A. N. Alexandrova, E. R. Hudson, and A. Derevianko

Physical Review Letters 134, 253801

Open paper

Nuclear clock

Photoinduced quenching of the ²²⁹Th isomer in a solid-state host

J. Terhune, R. Elwell, H. B. Tran Tan, U. C. Perera, et al.

Physical Review Research 7, L022062

Open paper

Nuclear clock

Design of new thorium nuclear clock materials based on polyatomic ions

Open paper

Nuclear clock

Proposal and theoretical investigation of ²²⁹Th-doped nonlinear optical crystals for compact solid-state clocks

Open paper

Nuclear clock

Radiative decay of the ²²⁹ᵐTh nuclear clock isomer in different host materials

Open paper

2024

Nuclear clock

²²⁹ThF₄ thin films for solid-state nuclear clocks

Open paper

Nuclear clock

Laser excitation of the ²²⁹Th nuclear isomeric transition in a solid-state host

Open paper

2019

Nuclear clock

The concept of laser-based conversion electron Mössbauer spectroscopy for a precise energy determination of ²²⁹ᵐTh

Open paper

2015

Nuclear clock

Radiative lifetime and energy of the low-energy isomeric level in ²²⁹Th

Open paper

Nuclear clock

Results of a Direct Search Using Synchrotron Radiation for the Low-Energy ²²⁹Th Nuclear Isomeric Transition

Open paper

2012

Instrumentation

Low-threshold ultraviolet solid-state laser based on a Ce³⁺:LiCaAlF₆ crystal resonator

Open paper

Nuclear clock

Optical spectroscopy of an atomic nucleus: Progress toward direct observation of the ²²⁹Th isomer transition

Open paper

2011

Nuclear clock

Progress towards fabrication of ²²⁹Th-doped high energy band-gap crystals for use as a solid-state optical frequency reference

Open paper

2010

Nuclear clock

Constraining the Evolution of the Fundamental Constants with a Solid-State Optical Frequency Reference Based on the ²²⁹Th Nucleus

Open paper

2009

Nuclear clock

Computer modelling of thorium doping in LiCaAlF₆ and LiSrAlF₆: application to the development of solid state optical frequency devices

Open paper