1. arXiv:1104.3177 Optical pulse-shaping for internal cooling of molecules Optical pulse-shaping for internal cooling of molecules Chien-Yu Lien, Scott Williams, and Brian Odom Department of Physics and Astronomy, Northwestern University International Symposium on Molecular Spectroscopy 66th Meeting 2011.06.24

2. Applications: Molecular clock Test on fundamental constant Quantum computation Cold chemistry. Internal Cooling !? -> Prepare molecules in desired low energy states Methods: Buffer gas cooling Supersonic expansion Stark deceleration Optical pumping.

3. What about rotational degree of freedom M. Viteau et al, Science, 2008, 321, 232–234.

4. Achieve rotational cooling in 10s of seconds P. F. Staanum et al., Nature Physics, 2010, 6, 271–274. T. Schneider et al., Nature Physics, 2010, 6, 275–278.

5. Apparatus – RF Paul trap pulse valve source chamber exp. chamber AlH + r 0 = 3 mm z 0 =15mm Ω rf = 2MHz Internal degrees of freedom are not cooled! Ba +

6. v” = 0 v” = 2 v” = 1 v’ = 0 v’ = 1 1500 cm -1 300 K ~ 200 cm -1 Diagonal Frank-Condon factors of AlH + AlH +

7. Rotational optical pumping in AlH + K’ J’ 3 2.5 2 1.5 1 0.5 K” J” 3 2 1 0 2.5 1.5 0.5 P −+−+ +−+− −+−+ ++++ −−−− + −−−− 3.5 2.5 pumping decay

8. Mirror Grating Mask Mirror Concave Mirror Pulse shaping Pillet’s group cooled the vibrational DOF with this technique

9. Better than the required 10 cm -1 for cooling AlH +

10. Data

11. PROC (Pulse-shaped Rotational Optical Cooling)

12. Rate Equation Simulation

14. 1 + 1’ REMPD state readout M. F. Guest and D. M. Hlrst, Chemical Physics Letters, 1981, 84, 167. P. J. Bruna and F. Grein, Physical Chemistry Chemical Physics, 2003, 5, 3140.

15. Conclusions This scheme cools internal DOF in 10μs compared to 10s of seconds Complementary to the work of Drewsen and Schiller’s groups Advantage of choosing AlH + : Diagonal FCFs Simple pulse-shaping Extension to other molecules: A second fs laser to repump v” > 0 population

16. Current Progress Pulse-shaped laser ready AlH sample generation ready Ion trap ready Vacuum system ready Next: start trapping!

17. More info.-- arXiv:1104.3177 Acknowledgement Thanks to: Prof. Brian Odom Scott Williams – laser spectrum Dr. Jason Nguyen – simulation Chris Seck And your attention!!

18. Addition slides in the back http://www.zazzle.com/geeksgetit