Rovibronic spectroscopy of sympathetically cooled CaH+

Spectroscopy;Coulomb crystal;Ion trapping;Laser cooling

Calvin, Aaron ; Perry, Joseph Chemistry and Biochemistry Sherrill, David Orlando, Thomas Raman, Chandra ; Perry, Joseph

University:Georgia Institute of Technology

Department:Chemistry and Biochemistry

关键词: Spectroscopy;    Coulomb crystal;    Ion trapping;    Laser cooling;   

Others  :  https://smartech.gatech.edu/bitstream/1853/60241/1/CALVIN-DISSERTATION-2018.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

CaH+ is an astrophysically relevant molecule with proposed applications in fundamental physics. We use CaH+ co-trapped with Doppler cooled Ca+ to perform spectroscopy using two-photon photodissociation with a frequency doubled, mode locked Ti:sapph laser. This method was used to measure the vibronic spectrum of the 11 Σ, v = 0 → 2 1Σ, v' = 0, 1, 2, 3 transitions. Spectroscopy on the deuterated isotopologue, CaD+ confirmed a revised assignment of the CaH+ vibronic levels and a disagreement with MS-CASPT2 theoretical calculations by approximately 700 cm-1. Updated high-level coupled-cluster calculations that include core-valence correlations reduce the disagreement between theory and experiment to 300 cm-1. The broad bandwidth of the pulsed Ti:sapph provided an advantage for the initial search for transitions, but did not allow spectral resolution of rotational transitions. Pulse shaping was applied to spectrally narrow the linewidth of the pulsed laser to obtain rotational constants for the 21 Σ, v' = 0, 1, 2, 3 and 11 Σ, v = 0 states. This measurement has value in the control of quantum states of the molecule for high precision measurements of rovibrational transitions using quantum logic. Molecule-cold atom collisions for possible buffer gas cooling can also be tested using this method.