Vibrational Spectroscopy of Cold Molecular Ions Ncamiso Khanyile Ken Brown Lab School of Chemistry and Biochemistry June 2014

2 Motivation and background Quantum computing Fundamental physics Cold atomic and molecular ions NASA jqi.umd.edu Redorbit

3 Why cold molecular ions Trapped and sympathetically cooled with atomic ions Long storage times allows for long interrogation times Low temperature reactions possible due non-Arrhenius behavior Can be prepared in low internal and external energies for greater precision and control Lack experimental data

4 Spectroscopic Tools Sympathetic Heating Spectroscopy (SHS) –Needs many photons to be scattered to induce observable heating Resonance Enhanced Multiphoton Dissociation (REMPD) –Can offer high precision measurements by coupling to dissociative channel Quantum Heating Spectroscopy (Q-SHS) –Observe heating of sidebands from scattered photons Quantum Logics Spectroscopy (QLS) –Highest precision but very difficult to implement

5 Sympathetic Cooling of Molecular Ions Roth B. et al., J. Phys. B: At., Mol., and Opt. Phys.38,3673(2005)

6 Spectroscopic Tools Sympathetic Heating Spectroscopy (SHS) Quantum Heating Spectroscopy (Q- SHS) Quantum Logics Spectroscopy (QLS) Resonance Enhanced Multiphoton Dissociation (REMPD)

7 Resonance Enhanced Multiphoton Dissociation Bressel, U.,et.al.,Phys. Rev. Lett. 108,183003(2012)

8 Previous experiments on CaH + Hansen, A.K.et.al., Ang. Chem. Int. Ed. 51,7960(2012)

9 REMPD on CaH + (ν 10 ←ν 0 )

10 REMPD on CaH + (ν 9 ←ν 0 )

11 Experimental setup

12 Experimental procedure

13 Availability of theoretical data Abe, M., et al., J.Phys. B: At. Mol. Opt. Phys. 43, (2010) CaH +

14 Results

15 REMPD on CaH + (ν 10 ←ν 0 ) Theory : nm Experiment: ± 2.3 nm

16 Triple photon dissociation

17 Expected Linewidth

18 REMPD on CaH + (ν 9 ←ν 0 ) Theory : nm Experiment: 887.6± 2.3nm

19 Discussion and conclusions Measured for the first time vibrational lines of CaH + Both lines exhibit peaks much narrower than the IR laser linewidth Explore the causes of the narrowness of the spectrum Measure the peaks with IR laser in CW mode instead of pulsed mode Use non-destructive techniques

20 Acknowledgements