Seres, J., Seres, E., & Schumm, T. (2026). Cascaded multi-harmonic generation in a β-BBO crystal reaching 133 nm from a single 800 nm pump beam. Journal of Optics, 28(6), Article 065501. https://doi.org/10.1088/2040-8986/ae729a

Seres, J., Seres, E., & Schumm, T. (2026). Simulating cascaded harmonics generation up to the sixth order in β-BBO. Photonics, 13(5), Article 436. https://doi.org/10.3390/photonics13050436

Ooi, T., Doyle, J. F., Zhang, C., Higgins, J. S., Ye, J., Beeks, K. A. A. G., Sikorsky, T., & Schumm, T. (2026). Frequency reproducibility of solid-state thorium-229 nuclear clocks. Nature, 650, 72–78. https://doi.org/10.1038/s41586-025-09999-5

Pimon, M., Kirschbaum, T., Schumm, T., Pálffy, A., & Grüneis, A. (2026). Density functional theory study of Th-doped LiCAF and LiSAF for nuclear clock applications. Physical Review B, 113(1), Article 014107. https://doi.org/10.1103/8hql-f6l6

Guan, M., Bartokos, M., Beeks, K. A. A. G., Fujimoto, H., Fukunaga, Y., Haba, H., Hiraki, T., Kasamatsu, Y., Kitao, S., Leitner, A., Masuda, T., Nagasawa, N., Okai, K., Ogake, R., Pimon, M., Pressler, M., Sasao, N., Schaden, F., Schumm, T., … Yoshimura, K. (2026). X-Ray-Induced Quenching of the Th²⁹⁹ Clock Isomer in CaF₂. Physical Review Letters, 136(1), Article 013203. https://doi.org/10.1103/75bb-thn7

Hiraki, T., Masuda, T., Takatori, S., Schaden, F., Bartokos, M., Beeks, K., Fukunaga, Y., Grüneis, A., Guan, M., Kazakov, G., LaGrange, T., Leitner, A., Morawetz, I., Ogake, R., Okai, K., Pimon, M., Pressler, M., Riebner, T. T., Sasao, N., … Yoshimura, K. (2026). Laser Mössbauer spectroscopy of ²²⁹Th in CaF₂. Science, 393(6813), 795–799. https://doi.org/10.1126/science.aea7978

Morawetz, I., Riebner, T. T., Toscani De Col, L., Schneider, F., Sempelmann, N., Schaden, F., Bartokos, M., Kazakov, G. A., Lahs, S., Beeks, K. A. A. G., Gerstenecker, B., Grüneis, A., Pimon, M., Schumm, T., Lal, V., Zitzer, G., Petrov, V., Tiedau, J., Okhapkin, M. V., & Peik, E. (2026). Continuous-wave laser absorption spectroscopy of the thorium-229 nucleus. Nature, 657, 626–631. https://doi.org/10.1038/s41586-026-11011-7

Beeks, K. A. A. G., Kazakov, G. A., Schaden, F., Morawetz, I., Toscani De Col, L., Riebner, T. T., Bartokos, M., Sikorsky, T., Schumm, T., Zhang, C., Ooi, T., Higgins, J. S., Doyle, J. F., Ye, J., & Safronova, M. S. (2025). Fine-structure constant sensitivity of the Th-229 nuclear clock transition. Nature Communications, 16, Article 9147. https://doi.org/10.1038/s41467-025-64191-7

O’Neil, G., Beeks, K., Hudson, E., Jeet, J., Leibrandt, D., Mallweger, M., Nam, S. W., Patra, S., Porat, G., Reddy, D., Schumm, T., Schoun, S. B., Seiferle, B., Schneider, C., von der Wense, L., Thirolf, P. G., Verma, V., Ye, J., & Zhang, C. (2025). Direct detection of the ≈ 8.4eV internal conversion energy of ^229mTh embedded in a superconducting nanowire. Physical Review C, 112(2), Article 024322. https://doi.org/10.1103/9v5w-b8k2

Schaden, F., Riebner, T. T., Morawetz, I., Toscani De Col, L., Kazakov, G. A., Beeks, K. A. A. G., Sikorsky, T., Schumm, T., Zhang, K., Lal, V., Zitzer, G., Tiedau, J., Okhapkin, M. V., & Peik, E. (2025). Laser-induced quenching of the Th-229 nuclear clock isomer in calcium fluoride. Physical Review Research (PRResearch), 7(2), Article L022036. https://doi.org/10.1103/PhysRevResearch.7.L022036

Guan, M., Bartokos, M., Beeks, K. A. A. G., Fukunaga, Y., Hiraki, T., Masuda, T., Miyamoto, Y., Ogake, R., Okai, K., Sasao, N., Schaden, F., Schumm, T., Shimizu, K., Takatori, S., Yoshimi, A., & Yoshimura, K. (2025). A method to detect the VUV photons from cooled ²²⁹Th:CaF₂ crystals. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 562, Article 165647. https://doi.org/10.1016/j.nimb.2025.165647

Takatori, S., Pimon, M., Pollitt, S., Bartokos, M., Beeks, K., Grüneis, A., Hiraki, T., Honma, T., Hosseini, N., Leitner, A., Masuda, T., Morawetz, I., Nitta, K., Okai, K., Riebner, T. T., Schaden, F., Schumm, T., Sekizawa, O., Sikorsky, T., … Yoshimura, K. (2025). Characterization of the thorium-229 defect structure in CaF₂ crystals. New Journal of Physics, 27(4), Article 043024. https://doi.org/10.1088/1367-2630/adce22

Higgins, J. S., Ooi, T., Doyle, J. F., Zhang, C., Ye, J., Beeks, K. A. A. G., Sikorsky, T., & Schumm, T. (2025). Temperature Sensitivity of a Thorium-229 Solid-State Nuclear Clock. Physical Review Letters, 134, Article 113801. https://doi.org/10.1103/PhysRevLett.134.113801

Nalikowski, K., Veryazov, V., Beeks, K. A. A. G., Schumm, T., & Krośnicki, M. (2025). Embedded cluster approach for accurate electronic structure calculations of  ²²⁹Th :CaF₂. Physical Review B, 111, Article 115103. https://doi.org/10.1103/PhysRevB.111.115103

Pineda, S. V., Chhetri, P., Bara, S., Elskens, Y., Casci, S., Alexandrova, A. N., Au, M., Athanasakis-Kaklamanakis, M., Bartokos, M., Beeks, K., Bernerd, C., Claessens, A., Chrysalidis, K., Cocolios, T. E., Correia, J. G., De Witte, H., Elwell, R., Ferrer, R., Heinke, R., … Yue, Z. (2025). Radiative decay of the ^229mTh nuclear clock isomer in different host materials. Physical Review Research (PRResearch), 7(1), Article 013052. https://doi.org/10.1103/PhysRevResearch.7.013052

Seres, J., Seres, E. J., Céspedes, E., Martínez de Olcoz Sainz, L., Zabala, M., & Schumm, T. (2024). Effects of Thickness and Grain Size on Harmonic Generation in Thin AlN Films. Photonics, 11(11), Article 1078. https://doi.org/10.3390/photonics11111078

Zhang, C., Ooi, T., Higgins, J. S., Doyle, J. F., von der Wense, L., Beeks, K., Leitner, A., Kazakov, G., Li, P., Thirolf, P. G., Schumm, T., & Ye, J. (2024). Frequency ratio of the ^229mTh nuclear isomeric transition and the ⁸⁷Sr atomic clock. Nature, 633, 63–70. https://doi.org/10.1038/s41586-024-07839-6

Hiraki, T., Okai, K., Bartokos, M., Beeks, K. A. A. G., Fujimoto, H., Fukunaga, Y., Haba, H., Kasamatsu, Y., Kitao, S., Leitner, A., Masuda, T., Guan, M., Nagasawa, N., Ogake, R., Pimon, M., Pressler, M., Sasao, N., Schaden, F., Schumm, T., … Yoshimura, K. (2024). Controlling ²²⁹Th isomeric state population in a VUV transparent crystal. Nature Communications, 15(1), Article 5536. https://doi.org/10.1038/s41467-024-49631-0

Seres, E. J., Seres, J., Martinez-de-Olcoz, L., & Schumm, T. (2024). Compact tunable 80 MHz repetition rate vacuum ultraviolet light source up to 10 eV: intracavity high harmonic generation by nonlinear reflection on a AlN nanofilm in a mode locked Ti:sapphire oscillator. Optics Express, 32(10), 17593–17605. https://doi.org/10.1364/OE.522309

Tiedau, J., Okhapkin, M. V., Zhang, K., Thielking, J., Zitzer, G., Peik, E., Schaden, F., Pronebner, T. T., Morawetz, I., Toscani De Col, L., Schneider, F., Leitner, A., Pressler, M., Kazakov, G., Beeks, K. A. A. G., Sikorsky, T., & Schumm, T. (2024). Laser Excitation of the Th-229 Nucleus. Physical Review Letters, 132(18), Article 182501. https://doi.org/10.1103/PhysRevLett.132.182501

Sikorsky, T., Pelczar, A., Schneider, S., & Schumm, T. (2024). Integrating superregenerative principles in a compact, power-efficient NMR/NQR spectrometer: A novel approach with pulsed excitation. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 1062, Article 169239. https://doi.org/10.1016/j.nima.2024.169239

Beeks, K., Sikorsky, T., Schaden, F., Pressler, M., Schneider, F. S., Koch, B., Pronebner, T. T., Werban, D. M., Hosseini, N., Kazakov, G., Welch, J. M., Sterba, J., Kraus, F., & Schumm, T. (2024). Optical transmission enhancement of ionic crystals via superionic fluoride transfer: Growing VUV-transparent radioactive crystals. Physical Review B, 109(9), Article 094111. https://doi.org/10.1103/PhysRevB.109.094111

Kirschbaum, T., Schumm, T., & Pálffy, A. (2024). Photoexcitation of the ²²⁹Th nuclear clock transition using twisted light. Physical Review C, 110(6), 1–16. https://doi.org/10.1103/PhysRevC.110.064326

Seres, J., Seres, E., Céspedes, E., Martinez-de-Olcoz, L., Zabala, M., & Schumm, T. (2023). Probing nonperturbative third and fifth harmonic generation on silicon without and with thermal oxide layer. Journal of Optics, 25(10), Article 105501. https://doi.org/10.1088/2040-8986/acefe4

Kraemer, S., Moens, J., Athanasakis-Kaklamanakis, M., Bara, S., Beeks, K. A. A. G., Chhetri, P., Chrysalidis, K., Claessens, A., Cocolios, T. E., Correia, J. G. M., Witte, H. D., Ferrer, R., Geldhof, S., Heinke, R., Hosseini, N., Huyse, M., Köster, U., Kudryavtsev, Y., Laatiaoui, M., … Wahl, U. (2023). Observation of the radiative decay of the ²²⁹Th nuclear clock isomer. Nature, 617(7962), 706–710. https://doi.org/10.1038/s41586-023-05894-z

Seres, J., Seres, E., Céspedes, E., Martínez de Olcoz, L., Zabala, M., & Schumm, T. (2023). Nonperturbative Generation of Harmonics by Nanometer-Scale Localized Electronic States on the Surface of Bulk Materials and Nano-Films. Optics, 4(1), 246–257. https://doi.org/10.3390/opt4010017

Beeks, K., Sikorsky, T., Rosecker, V., Pressler, M., Schaden, F., Werban, D., Hosseini, N., Rudischer, L., Schneider, F., Berwian, P., Friedrich, J., Hainz, D., Welch, J., Sterba, J., Kazakov, G., & Schumm, T. (2023). Growth and characterization of thorium-doped calcium fluoride single crystals. Scientific Reports, 13(1), Article 3897. https://doi.org/10.1038/s41598-023-31045-5

Pimon, M., Mohn, P., & Schumm, T. (2022). Band Gap Calculations for Thorium‐Doped LiCAF. Advanced Theory and Simulations, 5(10), Article 2200185. https://doi.org/10.1002/adts.202200185

Pimon, M., Grüneis, A., Mohn, P., & Schumm, T. (2022). Ab-Initio Study of Calcium Fluoride Doped with Heavy Isotopes. Crystals, 12(8), Article 1128. https://doi.org/10.3390/cryst12081128

Seres, E. J., Seres, J., & Schumm, T. (2022). Group delay dispersion tuned femtosecond Kerr-lens mode-locked Ti:sapphire laser. Optics Continuum, 1(4), 860–865. https://doi.org/10.1364/OPTCON.456954

Cizek, M., Pravdova, L., Pham, T. M., Lesundak, A., Hrabina, J., Lazar, J., Pronebner, T., Aeikens, E., Premper, J., Havlis, O., Velc, R., Smotlacha, V., Altmannova, L., Schumm, T., Vojtech, J., Niessner, A., & Cip, O. (2022). Coherent fibre link for synchronization of delocalized atomic clocks. Optics Express, 30(4), 5450–5464. https://doi.org/10.1364/OE.447498

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. https://doi.org/10.1038/s42254-021-00286-6

Masuda, T., Watanabe, T., Beeks, K., Fujimoto, H., Hiraki, T., Kaino, H., Kitao, S., Miyamoto, Y., Okai, K., Sasao, N., Seto, M., Schumm, T., Shigekawa, Y., Tamasaku, K., Uetake, S., Yamaguchi, A., Yoda, Y., Yoshimi, A., & Yoshimura, K. (2021). Absolute X-ray energy measurement using a high-accuracy angle encoder. Journal of Synchrotron Radiation, 28(1), 111–119. https://doi.org/10.1107/s1600577520014526

Nickerson, B. S., Pimon, M., Bilous, P. V., Gugler, J., Kazakov, G. A., Sikorsky, T., Beeks, K., Grüneis, A., Schumm, T., & Pálffy, A. (2021). Driven electronic bridge processes via defect states in ²²⁹Th -doped crystals. Physical Review A, 103(053120). https://doi.org/10.1103/physreva.103.053120

Peik, E., Schumm, T., Safronova, M. S., Pálffy, A., Weitenberg, J., & Thirolf, P. G. (2021). Nuclear clocks for testing fundamental physics. Quantum Science and Technology, 6(3), 034002. https://doi.org/10.1088/2058-9565/abe9c2

Seres, J., Seres, E., Serrat, C., & Schumm, T. (2021). High harmonic generation in AlN due to out-of-surface electron orbitals. OSA Continuum, 4(1), 47. https://doi.org/10.1364/osac.404942

Sikorsky, T., Geist, J., Hengstler, D., Kempf, S., Gastaldo, L., Enss, C., Mokry, C., Runke, J., Düllmann, C. E., Wobrauschek, P., Beeks, K. A. A. G., Rosecker, V., Sterba, J. H., Kazakov, G., Schumm, T., & Fleischmann, A. (2020). Measurement of the ²²⁹Th Isomer Energy with a Magnetic Microcalorimeter. Physical Review Letters, 125(14), Article 142503. https://doi.org/10.1103/physrevlett.125.142503

Nickerson, B. S., Pimon, M., Bilous, P. V., Gugler, J., Beeks, K. A. A. G., Sikorsky, T., Mohn, P., Schumm, T., & Pálffy, A. (2020). Nuclear Excitation of the ²²⁹Th Isomer via Defect States in Doped Crystals. Physical Review Letters, 125(3), Article 032501. https://doi.org/10.1103/physrevlett.125.032501

Pimon, M., Gugler, J., Mohn, P., Kazakov, G. A., Mauser, N., & Schumm, T. (2020). DFT calculation of (229)thorium-doped magnesium fluoride for nuclear laser spectroscopy. Journal of Physics: Condensed Matter, 32(25), 255503. https://doi.org/10.1088/1361-648x/ab7c90

Pohjalainen, I., Moore, I. D., Geldhof, S., Rosecker, V., Sterba, J., & Schumm, T. (2020). Gas cell studies of thorium using filament dispensers at IGISOL. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 484, 59–70. https://doi.org/10.1016/j.nimb.2020.08.012

Masuda, T., Yoshimi, A., Fujieda, A., Fujimoto, H., Haba, H., Hara, H., Hiraki, T., Kaino, H., Kasamatsu, Y., Kitao, S., Konashi, K., Miyamoto, Y., Okai, K., Okubo, S., Sasao, N., Seto, M., Schumm, T., Shigekawa, Y., Suzuki, K., … Yoshimura, K. (2019). X-ray pumping of the ²²⁹Th nuclear clock isomer. Nature, 573(7773), 238–242. https://doi.org/10.1038/s41586-019-1542-3

Seiferle, B., von der Wense, L., Bilous, P. V., Amersdorffer, I., Lemell, C., Libisch, F., Stellmer, S., Schumm, T., Düllmann, C. E., Pálffy, A., & Thirolf, P. G. (2019). Energy of the ²²⁹Th nuclear clock transition. Nature, 573(7773), 243–246. https://doi.org/10.1038/s41586-019-1533-4

Seres, J., Seres, E., Serrat, C., Young, E. C., Speck, J. S., & Schumm, T. (2019). All-solid-state VUV frequency comb at 160 nm using high-harmonic generation in nonlinear femtosecond enhancement cavity. Optics Express, 27(5), 6618. https://doi.org/10.1364/oe.27.006618

Stellmer, S., Shigekawa, Y., Rosecker, V., Kazakov, G. A., Kasamatsu, Y., Yasuda, Y., Shinohara, A., & Schumm, T. (2018). Towards an energy measurement of the internal conversion electron in the de-excitation of the Th-229 isomer. Physical Review C, 98(014317). https://doi.org/10.1103/physrevc.98.014317

Stellmer, S., Kazakov, G., Schreitl, M., Kaser, H., Kolbe, M., & Schumm, T. (2018). Attempt to optically excite the nuclear isomer in Th-229. Physical Review A, 97(062506). https://doi.org/10.1103/physreva.97.062506

Pigneur, M., Berrada, T., Bonneau, M., Schumm, T., Demler, E., & Schmiedmayer, J. (2018). Relaxation to a Phase-locked Equilibrium State in a One-dimensional Bosonic Josephson Junction. Physical Review Letters, 120(173601). https://doi.org/10.1103/physrevlett.120.173601

Seres, J., Seres, E., Serrat, C., & Schumm, T. (2018). Non-perturbative generation of DUV/VUV harmonics from crystal surfaces at 108 MHz repetition rate. Optics Express, 26(17), 21900. https://doi.org/10.1364/oe.26.021900

Yoshimi, A., Hara, H., Hiraki, T., Kasamatsu, Y., Kitao, S., Kobayashi, Y., Konashi, K., Masuda, R., Masuda, T., Miyamoto, Y., Okai, K., Okubo, S., Ozaki, R., Sasao, N., Sato, O., Seto, M., Schumm, T., Shigekawa, Y., Stellmer, S., … Yoshimura, M. (2018). Nuclear resonant scattering experiment with fast time response: Photonuclear excitation of ²⁰¹Hg. Physical Review C, 97(024607). https://doi.org/10.1103/physrevc.97.024607

Bilous, P. V., Kazakov, G. A., Moore, I. D., Schumm, T., & Pálffy, A. (2017). Internal conversion from excited electronic states of ²²⁹Th ions. Physical Review A, 95(3), 1–8. https://doi.org/10.1103/physreva.95.032503

Kazakov, G. A., & Schumm, T. (2017). Stability analysis for bad cavity lasers using inhomogeneously broadened spin-1/2 atoms as a gain medium. Physical Review A, 95(023839). https://doi.org/10.1103/physreva.95.023839

Kazakov, G. A., Bohnet, J., & Schumm, T. (2017). Prospects for a bad-cavity laser using a large ion crystal. Physical Review A, 96(023412). https://doi.org/10.1103/physreva.96.023412

Stellmer, S., Schreitl, M., Kazakov, G. A., Sterba, J. H., & Schumm, T. (2016). Feasibility study of measuring the ²²⁹Th nuclear isomer transition with ²³³U-doped crystals. Physical Review C, 94(1), Article 014302. https://doi.org/10.1103/physrevc.94.014302

Berrada, T., van Frank, S., Bücker, R., Schumm, T., Schaff, J.-F., Schmiedmayer, J., Julía-Díaz, B., & Polls, A. (2016). Matter-wave recombiners for trapped Bose-Einstein condensates. Physical Review A, 93(063620). https://doi.org/10.1103/physreva.93.063620

Winkler, G., Fellinger, J., Seres, J., Seres, E., & Schumm, T. (2016). Non-planar femtosecond enhancement cavity for VUV frequency comb applications. Optics Express, 24(5), 5253. https://doi.org/10.1364/oe.24.005253

Stellmer, S. P., Schreitl, M., & Schumm, T. (2015). Radioluminescence and photoluminescence of Th:CaF₂ crystals. Scientific Reports, 5, Article 15580. https://doi.org/10.1038/srep15580

Jäger, G., Berrada, T., Schmiedmayer, J., Schumm, T., & Hohenester, U. (2015). Parametric-squeezing amplification of Bose-Einstein condensates. Physical Review A, 92(053632). https://doi.org/10.1103/physreva.92.053632

Kazakov, G. A., & Schumm, T. (2015). Magic radio-frequency dressing for trapped atomic microwave clocks. Physical Review A, 91(023404). https://doi.org/10.1103/physreva.91.023404

Stellmer, S., Schreitl, M., Kazakov, G., Yoshimura, K., & Schumm, T. (2015). Towards a measurement of the nuclear clock transition in²²⁹Th. Journal of Physics: Conference Series, 012059.

Dessovic, P., Mohn, P., Jackson, R. A., Winkler, G., Schreitl, M., Kazakov, G., & Schumm, T. (2014). ²²⁹Thorium-doped calcium fluoride for nuclear laser spectroscopy. Journal of Physics: Condensed Matter, 26(10), 105402. https://doi.org/10.1088/0953-8984/26/10/105402

Kazakov, G. A., Schauer, V., Schwestka, J., Stellmer, S. P., Sterba, J. H., Fleischmann, A., Gastaldo, L., Pabinger, A., Enss, C., & Schumm, T. (2014). Prospects for rmeasuring the 229Th isomer energy using a metallic magnetic microcalorimeter. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 735, 229–239. https://doi.org/10.1016/j.nima.2013.09.012

van Frank, S., Negretti, A., Berrada, T., Bücker, R., Montangero, S., Schaff, J.-F., Schumm, T., Calarco, T., & Schmiedmayer, J. (2014). Interferometry with non-classical motional states of a Bose-Einstein condensate. Nature Communications, 5(4009). https://doi.org/10.1038/ncomms5009

Berrada, T., van Frank, S., Bücker, R., Schumm, T., Schaff, J.-F., & Schmiedmayer, J. (2013). Integrated Mach-Zehnder interferometer for Bose-Einstein condensates. Nature Communications, 4(2077). https://doi.org/10.1038/ncomms3077

Bücker, R., Berrada, T., van Frank, S., Schaff, J.-F., Schumm, T., Schmiedmayer, J., Jäger, G., Grond, J., & Hohenester, U. (2013). Vibrational state inversion of a Bose-Einstein condensate: optimal control and state tomography. Journal of Physics B: Atomic, Molecular and Optical Physics, 46(10), 104012. https://doi.org/10.1088/0953-4075/46/10/104012

Kazakov, G. A., & Schumm, T. (2013). Active optical frequency standard using sequential coupling of atomic ensembles. Physical Review A, 87(013821). https://doi.org/10.1103/physreva.87.013821

Perrin, A., Bücker, R., Manz, S., Betz, T., Koller, C., Plisson, T., Schumm, T., & Schmiedmayer, H.-J. (2012). Hanbury Brown and Twiss correlations across the Bose-Einstein condensation threshold. Nature Physics, 8(3), 195–198. https://doi.org/10.1038/nphys2212

Bücker, R., Hohenester, U., Berrada, T., van Frank, S., Perrin, A., Manz, S., Betz, T., Grond, J., Schumm, T., & Schmiedmayer, J. (2012). Dynamics of parametric matter-wave amplification. Physical Review A, 86(013638). https://doi.org/10.1103/physreva.86.013638

Kazakov, G. A., Litvinov, A., Romanenko, V. I., Yatsenko, L. P., Romanenko, A. V., Schreitl, M., Winkler, G., & Schumm, T. (2012). Performance of a ²²⁹Thorium solid-state nuclear clock. New Journal of Physics, 14, 083019.