Precision Molecular Ion Spectroscopy: A New Probe for New Physics

1. Precision Molecular Ion Spectroscopy: A New Probe for New Physics Brian Odom

2. milliKelvin Molecular Ion Research … a few years ago Michael Drewsen Aarhus Stephan Schiller Dusseldorf

3. milliKelvin Molecular Ion Research … today Michael Drewsen Aarhus Piet Schmidt PTB Brian Odom Northwestern YoshikiMoriwaki Toyama Ike Chuang MIT Tobias Schaetz MPI-Garching Stephan Schiller Dusseldorf Stephan Willitsch Basel Ken Brown Georgia Tech Eric Hudson UCLA Kunihiro Okada Tokyo Zhang Chaobo Nanyang

4. Precision AMO Spectroscopy ( for the “m”) Atomic microwave spectroscopy Atomic optical spectroscopy Best molecular spectroscopy

5. Why are Molecules so Far Behind? Atoms are easy …molecules are hard • Why cycle? • Laser cooling • Single atom detection

6. HEP-Inspired Molecular Possibilities Parity violation at molecular level Time-variation of constants e- p+ Fundamental electric dipole moments Nuclear spin-dependent (NSD) parity violation Molecular enhancement DeMille, et al, PRL 100, 023003 (2008) • 1-sigma constraints on PNC meson couplings • Haxton et al, Phys Rev C 65 045502

7. Time-Varying Constants Is this even possible? Kaluza-Klein, string theories allow/predict variations. What are the predictions? • Possibilities: • Continuing variation in time • “Phase-shift” behavior • Variation with space, not time • Variation with matter density, not time • We cannot predict rate or type of variation, but… electron-proton mass ratio m fine structure constant a

8. Units Ain’t Welcome In These Parts Experiment: Count the Cs clock ticks for a photon to cross H atom - Cs + Say that number changes from year to year… Conclusion: 1 s defined by Cs, c is defined…so rH is changing But…if 1 m were defined by rH , c still defined, we conclude that wCs is changing Talk of unitful constants changing obscures the physics

9. What Does This Have to Do with Dark Energy? ?

10. Strategies for a Hard Problem Strategy 1: The denominator approach Dm /m ≈ 10-6, T ≈ 109 years Data from Ultraviolet and Visible Echelle Spectrograph mounted on the Very Large Telescope of the European Southern Observatory Ubachs, Buning, Eikemma, and Reinhold, J Molec. Spect. 241, 155 (2007) Strategy 2: The numerator approach T ≈ 1 year… Dm/m < 10-15 ???

11. State of unConstant Affairs a m Quasar absorption lines: Laboratory: Al+/ Hg+ clock comparison: Quasar absorption lines: H2: Ubachs, Buning, Eikemma, and Reinhold, J Molec. Spect. 241, 155 (2007) NH3 / (CO, HCO+, HCN): Henkel et al, Astronomy and Astrophysics 440, 893 (2005) Combes and Wiklind, Astrophys J 486, L79 (1997) Laboratory: SF6 : Chardonnet, http://www.ptb.de/ACFC2007/present.htm m is way behind … because it needs molecules!

12. Molecular Degeneracy Can Help Some systematics, such as clock instability or Doppler shift, impose fractional frequency error Molecular complexity is definitely a good thing here

13. Ba+ Laser Cooling • Why Barium? • Heavy (effective sympathetic cooling of heavy molecular ions) • Cooling transition is most red option

14. Our First Ion Trap

15. Fluorescence Images of Trapped Ba+ • At low enough temperature (~ 0.1 K) crystallization occurs • Ba-138 is pushed left by light pressure

16. Trapped Barium Coulomb Crystals

17. … and Throw in Some Molecular Ions Ba+fluorescing ions BaH+ dark ions, (probably milliKelvin!) (Following Drewsen at Aarhus and Schiller at Dusseldorf)

18. Loading SiO+ First ablate Ba target Then ablate SiO target

19. Quantum Logic Spectroscopy, State Readout World’s best spectroscopy (QLS) is on a non-laser cooled ion…Why not on a molecular ion? Spectroscopy ion is hard to read out, but logic ion is easy Spectroscopy ion Logic ion Internal state Motional state n=1 n=0 ? n=1 n=0

20. Quantum Logic Spectroscopy, State Transfer World’s best spectroscopy (QLS) is on a non-laser cooled ion…Why not on a molecular ion? Spectroscopy ion is hard to read out, but logic ion is easy Spectroscopy ion Logic ion Internal state Motional state n=1 n=0 n=1 n=0

21. mQLS Trap Design 3 mm

22. mQLS Table and Trap

23. mQLS Vacuum Chamber Assembly

24. The People Doing the Work Postdocs Joan Marler Jason Nguyen Grad Students Chien-Yu Lien Yen-Wei Lin VaishnaviRajagopal Chris Seck David Tabor Ming-FengTu Undergrads Marc Bourgeois Greg McGlynn Ingrid Ringler Lauren Ruth Scott Williams … andThe People Paying for It IGERT Quantum Coherent Optical and Matter Systems

25. Extras…

26. Sounds Great.What’s the Catch?

27. Rotational Cooling of Hydrides Schiller and Drewsen groups (2010) • What would still be nice? • Faster cooling • Applicable to heavier species

28. Cool Rotations into Electronic Excitation? We would like diagonal Franck Condon Factors

29. Femtosecond Pulse Shaping 1 cm-1 resolution currently achieved

30. Pulse-Shaping for AlH+ Rotational Cooling Current resolution is sufficient for cooling

31. Simulation of AlH+ Rotational Cooling Expect ~7 ms cooling timescale (compare with 10 s timescale of vibrational excitation technique)

32. Review: Radiofrequency Ion Traps ~ 5 mm + - - http://www.exphy.uni-duesseldorf.de/ResearchInst +

33. Review: Radiofrequency Ion Traps ~ 5 mm - + + http://www.exphy.uni-duesseldorf.de/ResearchInst -