| Zugriffsnummer | 28215 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Minimizing time dilation in ion traps: towards an optical clock with Coulomb crystals |
| Autor(in); Institution |
Mehlstäubler, Tanja E.; 4.4, Zeit und Frequenz, PTB-Braunschweig
Pyka, Karsten; QUEST Institute for Experimental Quantum Metrology, PTB-Braunschweig
Keller, Jonas; QUEST Institute for Experimental Quantum Metrology, PTB-Braunschweig
Herschbach, Norbert; QUEST Institute for Experimental Quantum Metrology, PTB-Braunschweig
Meier, David-Marcel; QUEST Institute for Experimental Quantum Metrology, PTB-Braunschweig
Kuhlmann, Kristijan; QUEST Institute for Experimental Quantum Metrology, PTB-Braunschweig
Okhapkin, Maksim; 4.4, Zeit und Frequenz, PTB-Braunschweig
Ignatovich, Stepan; Institute of Laser Physics, Novosibirsk, RUSSIA
|
| Quelle/Jahr | 2012 IEEE International Frequency Control Symposium proceedings:(2012), 253 - 254 |
| Availability | [CD-ROM] |
| ISBN | 978-1-457-71819-9 (CD-ROM) ; 978-1-4577-1821-2 (print) |
| DOI | |
| Verlag | Piscataway, NJ: IEEE Service Center |
| Konferenzangaben | IFCS 2012, Baltimore, Md., 21-24, May, 2012, USA |
| Zusammenfassung | We present the status of our new experiment to laser-cool linear chains of 172Yb+ and 115In+ ions for an optical clock based on the 1S0-3P0 transition in 115In+. Owing to the quadrupole moment free clock-states several indium ions can be trapped and interrogated without ion number and position dependent frequency shifts. The aim is to create a novel optical frequency standard with improved short-term stability and a fractional long-term instability reaching down to 10-18 with relaxed requirements regarding the frequency stability of the clock laser system. Due to a higher signal-to-noise ratio in the atomic signal and shorter locking times a fractional frequency instability of 1×10-16 over 10 s is sufficient to achieve quantum projection noise limited clock performance. This becomes in reach with state-of-the-art reference cavities with a length of a few tens of cm. We detail on the systematic frequency shifts of such an optical clock and show that a fractional inaccuracy of 10-18 can be reached. Largest systematic frequency shifts limiting today’s best optical clocks and hindering the scaling to many ions are due to on-axis micromotion and excess heating rates. Based on precise finite element calculations we present a design for an improved linear ion trap that can accommodate several tens of ions for optical clock operation. In a prototype of this trap based on glass reinforced thermoset laminate, we successfully have trapped and laser-cooled Coulomb crystals of 172Yb+ ions that are used to characterize the trap and to sympathetically cool 115In+ ions. To avoid phase shifts and reduce rf-noise UHV proof RC filters are attached directly on the trap boards and a resonant tank circuit with a high quality factor was realized for the trap drive. The on-axis micromotion is characterized using photo-correlation spectroscopy. We were able to demonstrate a sensitivity to 2nd order Doppler shifts below 10-19 and compare on-axis rf fields with our calculations. Already in the prototype trap we could demonstrate an area of more than 60 μm, where the fractional frequency shifts due to time dilation are below 10-18 for both In+ and Yb+ ions. For clock spectroscopy and sideband-cooling two ultra-stable laser systems are set-up. With a simple ULE resonator design (spacer length 12 cm), we have demonstrated a fractional frequency instability reaching down to 6×10-16 between 1 to 10 s. For a 30 cm long cavity a vibration insensitive design based on FEM calculations in collaboration with the NPL is tested. |
Zitierung
Mehlstäubler, T. E., Pyka, K., Keller, J., Herschbach, N., Meier, D.-M., Kuhlmann, K., Okhapkin, M., & Ignatovich, S. (2012). Minimizing time dilation in ion traps: towards an optical clock with Coulomb crystals. IFCS 2012, Baltimore, Md., 21-24, May, 2012, USA. https://doi.org/10.1109/fcs.2012.6243653