Publications

An Optical Atomic Clock Based on a Highly Charged Ion

S. A. King, L. J. Spieß, P. Micke, A. Wilzewski, T. Leopold, E. Benkler, R. Lange, N. Huntemann, A. Surzhykov, V. A. Yerokhin, J. R. Crespo López-Urrutia, and P. O. Schmidt, An Optical Atomic Clock Based on a Highly Charged Ion, Nature 611, pp. 43-47 (2022), https://doi.org/10.1038/s41586-022-05245-4

Algorithmic Ground-State Cooling of Weakly Coupled Oscillators Using Quantum Logic

S. A. King, L. J. Spieß, P. Micke, A. Wilzewski, T. Leopold, J. R. Crespo López-Urrutia, and P. O. Schmidt, Phys. Rev. X 11, 041049 (2021), https://doi.org/10.1103/PhysRevX.11.041049

Coherent laser spectroscopy of highly charged ions using quantum logic

P. Micke, T. Leopold, S. A. King, E. Benkler, L. J. Spieß, L. Schmöger, M. Schwarz, J. R. Crespo López-Urrutia and P. O. Schmidt , Coherent laser spectroscopy of highly charged ions using quantum logic, Nature 578, pp. 60-65 (2020), https://doi.org/10.1038/s41586-020-1959-8

Closed-cycle, low-vibration 4 K cryostat for ion traps and other applications

P. Micke, J. Stark, S. A. King, T. Leopold, T. Pfeifer, L. Schmöger, M. Schwarz, L. J. Spieß, P. O. Schmidt, J. R. Crespo López-Urrutia, Review of Scientific Instruments 90, 065104 (2019), https://doi.org/10.1063/1.5088593

A cryogenic radio-frequency ion trap for quantum logic spectroscopy of highly charged ions

Tobias Leopold, Steven A. King, Peter Micke, Amado Bautista-Salvador, Jan C. Heip, Christian Ospelkaus, José R. Crespo López-Urrutia, Piet O. Schmidt,Review of Scientific Instruments 90, 073201 (2019), https://doi.org/10.1063/1.5100594

Highly charged ions: Optical clocks and applications in fundamental physics

M. G. Kozlov, M. S. Safronova, J. R. Crespo López-Urrutia, and P. O. Schmidt, Highly charged ions: Optical clocks and applications in fundamental physics, Rev. Mod. Phys 90, 045005 (2018), https://doi.org/10.1103/RevModPhys.90.045005

A self-injection locked DBR laser for laser cooling of beryllium ions

Steven A. King, Tobias Leopold, Premjith Thekkeppatt, Piet O. Schmidt, Applied Physics B, 124:214 (2018). doi:10.1007/s00340-018-7080-0

The Heidelberg compact electron beam ion traps

Peter Micke, S. Kühn, L. Buchauer, J. R. Harries, T. M. Bücking, et al., Review of Scientific Instruments 89, 063109 (2018). doi:10.1063/1.5026961

A tunable low-drift laser stabilized to an atomic reference

Tobias Leopold, Lisa Schmöger, Stefanie Feuchtenbeiner, Christian Grebing, Peter Micke, et al., Applied Physics B, 122:236 (2016). doi:10.1007/s00340-016-6511-z

Deceleration, precooling, and multi-pass stopping of highly charged ions in Be⁺ Coulomb crystals

Schmöger, L., Schwarz, M., Baumann, T. M., Versolato, O., Piest, B., Pfeifer, T., et al., Review of Scientific Instruments, 86(10):103111 (2015). doi:10.1063/1.4934245

Identifications of 5s_1/2−5p_3/2 and 5s²−5s5p EUV transitions of promethium-like Pt, Ir, Os and Re

Bekker, H., Versolato, O. O., Windberger, A., Oreshkina, N., Schupp, R., Baumann, T. M., et al., Journal of Physics B, 48(14):144018 (2015). doi:10.1088/0953-4075/48/14/144018

Coulomb crystallization of highly charged ions

Schmöger, L., Versolato, O., Schwarz, M., Kohnen, M., Windberger, A., Piest, B., et al., Science, 347(6227), 1233-1236 (2015). doi:10.1126/science.aaa2960

Identification of the Predicted 5s−4f Level Crossing Optical Lines with Applications to Metrology and Searches for the Variation of Fundamental Constants

Windberger, A., Crespo López-Urrutia, J. R., Bekker, H., Oreshkina, N., Berengut, J., Bock, V., et al., Physical Review Letters, 114(15):150801 (2015). doi:10.1103/PhysRevLett.114.150801

Cryogenic linear Paul trap for cold highly charged ion experiments

Schwarz, M., Versolato, O., Windberger, A., Brunner, F. R., Ballance, T., Eberle, S. N., et al., Review of Scientific Instruments, 83(8):083115, pp. 1-10 (2012). doi:http://link.aip.org/link/doi/10.1063/1.4742770

other relevant work:

Efficient rotational cooling of Coulomb-crystallized molecular ions by a helium buffer gas.

Hansen, A. K., Versolato, O., Kłosowski, Ł., Kristensen, S. B., Gingell, A., Schwarz, M., Windberger, A., Ullrich, J., Crespo López-Urrutia, J., & Drewsen, M. (2014), Nature, 508(7494), 76-79. doi:10.1038/nature12996.

Decay Rate Measurement of the First Vibrationally Excited State of MgH+ in a Cryogenic Paul Trap.

Versolato, O., Schwarz, M., Hansen, A. K., Gingell, A. D., Windberger, A., Kłosowski, Ł., Ullrich, J. H., Jensen, F., Crespo López-Urrutia, J. R., & Drewsen, M. (2013). Physical Review Letters, 111(5): 053002. doi:10.1103/PhysRevLett.111.053002.

Emission and Laser Spectroscopy of Trapped Highly Charged Ions in Electron Beam Ion Traps.

Crespo López-Urrutia, J. R., & Harman, Z. (2014). In W. Quint, & M. Vogel (Eds.), Fundamental Physics in Particle Traps (pp. 315-373). Berlin u.a.: Springer.

Coronium in the laboratory: measuring the Fe XIV green coronal line by laser spectroscopy.

Schnorr, K., Mäckel, V., Oreshkina, N., Augustin, S., Brunner, F. R., Harman, Z., Keitel, C. H., Ullrich, J. H., & Crespo López-Urrutia, J. R. (2013). The Astrophysical Journal, Supplement Series, 776(2): 121. doi:10.1088/0004-637X/776/2/121

Laser Spectroscopy on Forbidden Transitions in Trapped Highly Charged Ar¹³⁺ Ions.

Mäckel, V., Klawitter, R., Brenner, G., Crespo Lopez-Urrutia, J., & Ullrich, J. H. (2011). Physical Review Letters, 107(14): 143002. doi:10.1103/PhysRevLett.107.143002.

Spectroscopy using quantum logic.

P. O. Schmidt, T. Rosenband, C. Langer, W. M. Itano, J. C. Bergquist, D. J. Wineland, Science 309, 749–752 (2005). doi:10.1126/science.1114375 pmid:16051790