Vibrational Spectroscopy of Cold Molecular Ions

Vibrational Spectroscopy of Cold Molecular Ions

Ncamiso Khanyile

Ken Brown Lab

School of Chemistry and Biochemistry

June 2014

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Motivation and background Motivation and background

Quantum computing Fundamental physics

Cold atomic and molecular ions NASA

jqi.umd.edu

Redorbit

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Why cold molecular ions 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

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Sympathetic Cooling of Molecular IonsSympathetic Cooling of Molecular Ions

Roth B. et al., J. Phys. B: At., Mol., and Opt. Phys.38,3673(2005)

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Spectroscopic Tools Spectroscopic Tools

• Sympathetic Heating Spectroscopy

(SHS)

• Quantum Heating Spectroscopy (Q-

SHS)

• Quantum Logics Spectroscopy (QLS)

• Resonance Enhanced Multiphoton

Dissociation (REMPD)

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Resonance Enhanced Multiphoton DissociationResonance Enhanced Multiphoton Dissociation

Bressel, U.,et.al.,Phys. Rev. Lett. 108,183003(2012)

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Previous experiments on CaH+Previous experiments on CaH+

Hansen, A.K.et.al., Ang. Chem. Int. Ed. 51,7960(2012)

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REMPD on CaH+(ν10←ν0)REMPD on CaH+(ν10←ν0)

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REMPD on CaH+(ν9←ν0)REMPD on CaH+(ν9←ν0)

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Experimental setup Experimental setup

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Experimental procedure Experimental procedure

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Availability of theoretical data Availability of theoretical data

Abe, M., et al., J.Phys. B: At. Mol. Opt. Phys. 43, 245102(2010)

CaH+

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Results Results

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REMPD on CaH+(ν10←ν0)

Theory : 813.8 nm

Experiment: 814.8 ± 2.3 nm

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Triple photon dissociation Triple photon dissociation

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Expected LinewidthExpected Linewidth

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REMPD on CaH+(ν9←ν0)REMPD on CaH+(ν9←ν0)

Theory : 887.19 nm

Experiment: 887.6± 2.3nm

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Discussion and conclusions 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

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Acknowledgements Acknowledgements

http://ww2.chemistry.gatech.edu/brownlab/