Abstract
We investigate the photoassociation dynamics of cold NaRb molecule controlled by an asymmetric laser pulse called slowly-turned-on and rapidly-turned-off (STRT) laser pulse. This new shaped laser pulse has a remarkable merit, compared with the typical Gauss-type pulses, so that we can efficiently associate molecules with the state expected instead of going back to the continuum state. Using the three-state model, we solve the quantum mechanical equation with the “split operator-Fourier transform” method under the rotating-wave approximation (RWA) in propagation of the wave packet. By the projection of the obtained wave function onto each vibrational state, we can get the vibrational population of the ground electronic state. The results reveal that, with the STRT laser pulse, an efficient photoassociation process can be achieved and the vibrational distribution in the ground state can be controlled by the laser parameters.
Similar content being viewed by others
References
Li G X, Huang G M, Peng J S. Coherent population trapping in multilevel laser-induced continuum structure system including cascade two-photon processes. Chin Phys, 1998, 7(6): 422–431
Eramo R, Cavalier S, Fini L, et al. Observation of a laser-induced structure in the ionization continuum of sodium atoms using photoelectron energy spectroscopy. J Phys B, 1997, 30(17): 3789–3796
Faucher O, Hertz E, Lavorel B, et al. Observation of laser-induced continuum structure in the NO molecule. J Phys B, 1999, 32(18): 4485–4493
Wang L R, Ma J, Ji W B, et al. Research on ultracold cesium molecule long-range states by high-resolution photoassociative spectroscopy. Sci China Ser G-Phys Mech Astron, 2008, 51(2): 147–156
Bethlem H L, Berden G, Crompvoets F M H, et al. Electrostatic trapping of ammonia molecules. Nature, 2000, 406: 491–494
Thorsheim H R, Weiner J, Julienne P S. Laser-induced photoassociation of ultracold sodium atoms. Phys Rev Lett, 1987, 58(23): 2420–2423
Juarros E, Kirby K, Côté R. Laser-assisted ultracold lithium-hydride molecule formation: Stimulated versus spontaneous emission. J Phys B, 2006, 39: S965–S979
Sage J M, Sainis S, Bergeman T, et al. Optical production of ultracold polar molecules. Phys Rev Lett, 2005, 94(20): 203001
Vatasescu M. Formation of cold molecules by shaping with light the short-range interaction between cold atoms: Photoassociation with strong laser pulses. J Phys B, 2009, 42(16): 165303
Luc-Koenig E, Masnou-Seeuws F, Vatasescu M. Optimizing the photoassociation of cold atoms by use of chirped laser pulses. Eur Phys J D, 2004, 31(2): 239–262
Wright M J, Gensemer S D, Vala J. Control of ultracold collisions with frequency-chirped light. Phys Rev Lett, 2005, 95(6): 063001
Koch C P, Kosloff R, Luc-Koenig E, et al. Photoassociation with chirped laser pulses: Calculation of the absolute number of molecules per pulse. J Phys B, 2006, 39(19): S1017
Zhang W, Huang Y, Cong S L, et al. Efficient photoassociation with a slowly-turned-on and rapidly-turned-off laser field. Phys Rev A, 2010, 82(6): 063411
Chu T S, Han K L. Nonadiabatic time-dependent wave packet study of the D++H2 reaction system. J Phys Chem A, 2005, 109(10): 2050–2056
Chu T S, Zhang Y, Han K L. The time-dependent quantum wave packet approach to the eletronically nonadiabatic processes in chemical reactions. Int Rev Phys Chem, 2006, 25(1–2): 201–235
Chu T S, Han K L. Effect of Coriolis coupling in chemical reaction dynamics. Phys Chem Chem Phys, 2008, 10(18): 2431–2441
Meng Q T, Han K L, Lou N Q, et al. Theoretical study of the femtosecond-resoved photoelectron spectrum of the NO molecule. Phys Rev A, 2003, 67(6): 063202
Zhang H, Han K L, He G Z, et al. A real time dynamical calculation of 1 2 H-photodissociation. Chem Phys Lett, 1997, 271(4–6): 204–208
Hu J, Han K L, He G Z. Correlation quantum dynamics between an electron and D +2 molecule with attosecond resolution. Phys Rev Lett, 2005, 95(12): 123001
Meng Q T, Zhang Q G, Han K L. Time-dependent wavepacket approach to the influence of intense fields on the population of molecular excited states. Chem Phys, 2005, 316(1–3): 93–98
Meng Q T, Yang G H, Han K L. Time-dependent wave packet approach to Rabi oscillation in strong laser field. Int J Quantum Chem, 2003, 95(1): 30–36
Ma N, Wang M S, Yang C L, et al. Theoretical study of the influence of intense femtosecond laser field on the evolution of the wave packet and the population of NaRb molecule. Chin Phys B, 2010, 19(2): 023301
Band Y B, Julienne P S. Ultracold-molecule production by laser-cooled atom photoassociation. Phys Rev A, 1995, 51(6): R4317–R4320
Sugawara Y, Goban A, Minemoto S, et al. Laser-field-free molecular orientation with combined electrostatic and rapidly-turned-off laser fields. Phys Rev A, 2008, 77(3): 031403
Muramatsu M, Hita M, Minemoto S, et al. Field-free molecular orientation by an intense nonresonant two-color laser field with a slow turn on and rapid turn off. Phys Rev A, 2009, 79(1): 011403
Niu Y Y, Wang R, Cong S L, et al. Photoassociation reactions H+D+ and H++D in ultrashort pulse laser fields. Chin Phys lett, 2007, 24(12): 3400–3403
Zhang C Z, Zheng B, Meng Q T, et al. Theoretical simulation of the photoassociation process for NaCs. Chin Phys B, 2013, 22(2): 023401
Aymar M, Dulieu O. Calculations of transition and permanent dipole of heteronuclear alkali dimers NaK, NaRb and NaCs. Mol Phys, 2007, 105(11–12): 1733–1742
Feit M D, Fleck J A, Steiger A. Solution of the Schrödinger equation by a spectral method. J Comput Phys, 1982, 47: 412–433
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhang, C., Zheng, B., Niu, Y. et al. Photoassociation of NaRb with an asymmetric laser pulse. Sci. China Phys. Mech. Astron. 57, 1879–1884 (2014). https://doi.org/10.1007/s11433-013-5251-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11433-013-5251-x