Speaker
Description
K. Kiendlhofer1,2,3, M. Glantschnig1,2,3, M. Klammer1,4, M. Kromrey2,3, A. Woyke1,5, S. Aucther1, Y. Colombe1, A. Kulosa2, T. Mehlstäubler2,3,6, C. Rössler1
1 Infineon Technologies Austria AG, Villach, Austria
2 Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
3 Institute for Quantum Optics, Leibniz University of Hannover, Hannover, Germany
4 Institute for Applied Physics, TU Wien, Vienna, Austria
5 Federal Polytechnic School of Lausanne (EPFL), Lausanne, Switzerland
6 Laboratory for Nano and Quantum Engineering, Leibniz University of Hannover, Hannover, Germany
Optical ion clocks have previously achieved relative accuracies below 10-18 [1]. Such clocks have applications in satellite navigation [2], communication protocols [3], geodesy [4], and precision probing of fundamental physics such as the predictions of general relativity [5].
High-accuracy single ion clocks require long interrogation times, which limits their feasibility for a commercial product. In this project, a multi-ion trap will be fabricated. Every ion in a multi-ion trap has a different frequency shift depending on its local environment. If this challenge is overcome, multiple ions enable more elaborate interrogation schemes as well as significantly shorter interrogation times [6]. Industrial microfabrication can enable inexpensive and repeatable fabrication of large numbers of scalable ion traps.
One of the leading contributions to the clock’s uncertainty budget is thermal radiation from the trap’s surfaces. It induces an AC Stark shift that changes the clock transition frequency significantly, even when choosing the ion species accordingly. In order to achieve competitive accuracy, the trap’s temperature must be known up to tenths of a Kelvin [7]. Due to the scaling of thermal radiation intensity with temperature, the inaccuracy grows with trap temperature at constant temperature variation. This is why the trap should present low resistance and low capacitance to the RF supply, and why the material choice should minimise RF dissipation [7]. In this project, the RF resistance is reduced by developing new types of conducting wafer bonds for ion traps and by developing a process to fabricate through-substrate-vias to contact the top wafer electrodes.
Silicon substrate exhibits higher RF dissipation than glass, making glass substrate the first choice [8]. However, silicon substrate enables more sophisticated fabrication techniques, which could enable more complicated multilayer metal stacks [9] as well as integrated photonic layers in the future. The trade-off between silicon and glass substrate will be evaluated through electromagnetic and thermal simulation in this project.
[1] M. C. Marshall et al. 2025, Physical Review Letters 135, 033201.
[2] G. Michalak et al. 2021, Advances in Space Research, Volume 68, Issue 12, Pages 4753-4782.
[3] V. Martin et al. 2021, EPJ Quantum Technology. 8. 10.1140/epjqt/s40507-021-00108-9.
[4] T. Mehlstäubler et al. 2018, Rep. Prog. Phys. 81 064401.
[5] Andrei Derevianko et al. 2022, Quantum Sci. Technol. 7 044002.
[6] J. Keller et al. 2019, PHYSICAL REVIEW A 99, 013405.
[7] Nordmann et al. 2020, Rev. Sci. Instrum. 91, 111301.
[8] M. Dietl et al. 2025, Adv Quantum Technol.8, no. 11.
[9] S. Auchter et al. 2022 Quantum Sci. Technol. 7 035015
| Academic level | PhD student |
|---|