Quantum control of the yield of a chemical reaction

Pastirk, Igor; Brown, Emily J.; Zhang, Qingguo; Dantus, Marcos

doi:10.1063/1.475849

Cited by 65 publications

(70 citation statements)

References 35 publications

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“…The application of chirped pulses to shape nuclear wave packets and enhance or suppress vibrational coherence was developed by Ruhman and Kosloff [38]. Coherent control with an order of magnitude enhancement has been seen in a case that applied controlled second order dispersion [39]. The experimental ability to achieve high resolution active amplitude and phase shaping of femtosecond pulses has also led to the application of arbitrary search algorithms that use experimental feedback as fitness parameters to arrive at very complex pulses [40].…”

Section: Optical Control Of Population Transfer In Pypmentioning

confidence: 99%

Populations and coherence in femtosecond time resolved X-ray crystallography of the photoactive yellow protein

Hutchison

Thor

2017

International Reviews in Physical Chemistry

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Ultrafast X-ray crystallography of the Photoactive Yellow Protein with femtosecond delays using an X-ray Free Electron Laser has successfully probed the dynamics of an early FranckCondon species. The femtosecond pump-probe application of protein crystallography represents a new experimental regime that provides an X-ray structural probe for coherent processes that were previously accessible primarily using ultrafast spectroscopy. We address how the optical regime of the visible pump, that is necessary to successfully resolve ultrafast structural differences, affects the motions that are measured using the technique. The subpicosecond photochemical dynamics in PYP involves evolution of a mixture of electronic ground and excited state populations. Additionally, within the dephasing time structural motion include vibrational coherence arising from excited states, the ground state and a ground state intermediate under experimental conditions used for ultrafast crystallography. Intense optical pulses are required to convert population levels in PYP crystals that allow detection by X-ray crystallography, but the compromise currently needed for the optical bandwidth and power has consequences with regard to the contributions to the motions that are experimentally measured with femtosecond delays. We briefly review the ultrafast spectroscopy literature of the primary photoreactions of PYP and discuss relevant physical models taken from coherent control and femtosecond coherence spectroscopy literature that address both the population transfer as well 2 as the vibrational coherences. We apply linear response theory, with the additional use of a high power approximation, of on-resonance impulsive vibrational coherence in the ground state and the non-impulsive coherence in the excited state and discuss experimental approaches to manipulate the coherence contributions. The results are generalised and extended to discuss the future capabilities of high repetition rate XFEL instruments providing enhanced sensitivity to perform the crystallographic equivalent of an impulsive Raman measurement of vibrational coherence.

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Section: Optical Control Of Population Transfer In Pypmentioning

confidence: 99%

Populations and coherence in femtosecond time resolved X-ray crystallography of the photoactive yellow protein

Hutchison

Thor

2017

International Reviews in Physical Chemistry

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“…[13][14][15] A different approach using interference between competing paths developed by Shapiro et al is exemplified by the experimental demonstration of the control of branching ratio of Na 2 dissociating into sodium atoms in different electronic states. [16][17][18] Inverse quantum mechanical control to obtain appropriate field for tracking dynamics was also explored. 19,20 Artificial intelligence and learning algorithm based experimental set-ups [21][22][23][24][25] are also capable of providing a suitable laser field for prescribed dynamics, which prepare reactants in specific states to follow a desired reaction path.…”

Section: Introductionmentioning

confidence: 99%

Controlling dynamics in diatomic systems

Singh

2007

J Chem Sci

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Controlling molecular energetics using laser pulses is exemplified for nuclear motion in two different diatomic systems. The problem of finding the optimized field for maximizing a desired quantum dynamical target is formulated using an iterative method. The method is applied for two diatomic systems, HF and OH. The power spectra of the fields and evolution of populations of different vibrational states during transitions are obtained.

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“…The effect of chirped femtosecond laser pulses in multiphoton excitation was early on studied in molecules such as Na 2 , 45 I 2 , 30 and CH 2 I 2 , 31 and recently in systems such as N 2 ͑Ref. 46͒ and polyatomic fragmentation.…”

Section: Previous Chirp Experiments Using Lif or Tof-mass Detectionmentioning

confidence: 99%

“…A pioneering study on the enhancement of multiphoton absorption in I 2 using chirped pulses around 600 nm was reported by Wilson and co-workers. 30 Femtosecond pulse chirping was applied by Dantus and co-workers 31 to control the photodissociation reaction of CH 2 I 2 monitoring the concerted release of the I 2 molecule by fluorescence. More recently, the group of Weinacht has reported several studies using pump-probe spectroscopy to study wavepacket dynamics and control in halomethanes.…”

Section: Introductionmentioning

confidence: 99%

Toward elucidating the mechanism of femtosecond pulse shaping control in photodynamics of molecules by velocity map photoelectron and ion imaging

Irimia

Janssen

2010

The Journal of Chemical Physics

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High-resolution threshold photoelectron study of the propargyl radical by the vacuum ultraviolet laser velocitymap imaging method J. Chem. Phys. 135, 224304 (2011) Competitive ionization processes of anthracene excited with a femtosecond pulse in the multi-photon ionization regime J. Chem. Phys. 135, 214310 (2011) Interaction of nanosecond laser pulse with tetramethyl silane (Si(CH3)4) clusters: Generation of multiply charged silicon and carbon ions AIP Advances 1, 042164 (2011) Photoelectron spectroscopy of the molecular anions, Li3O and Na3O J. Chem. Phys. 135, 164308 (2011) Interpretation of the photoelectron spectra of superalkali species: Li3O and Li3O J. Chem. Phys. 135, 164307 (2011) Additional information on J. Chem. Phys. The control of photofragmentation and ionization in a polyatomic molecule has been studied by femtosecond chirped laser pulse excitation and velocity map photoelectron and ion imaging. The experiments aimed at controlling and investigating the photodynamics in CH 2 BrCl using tunable chirped femtosecond pulses in the visible wavelength region 509-540 nm at maximum intensities of about 4 ϫ 10 13 W / cm 2 . We observe that the time-of-flight mass spectra as well as the photoelectron images can be strongly modified by manipulating the chirp parameter of ultrashort laser pulses. Specifically, a strong enhancement of the CH 2 Cl + / CH 2 BrCl + ion ratio by a factor of five and changes in the photoelectron spectra are observed for positively chirped pulses centered near 520 nm. These changes are only observed within a narrow window of wavelengths around 520 nm and only for positively chirped pulses. From the combination of the photoelectron spectra and the ion recoil energy of the CH 2 Cl + fragment we can deduce that the parent ionization and fragmentation is induced by a multiphoton excitation with five photons. The photoelectron images and the fragment ion images also provide the anisotropy ͑␤-parameter͒ of the various electron bands and fragment ions. We conclude that multiphoton excitation of the highest occupied 22aЈ and 8aЉ CH 2 BrCl molecular orbitals of Br-character are both involved in the five-photon ionization, however, only excitation of the 22aЈ orbital appears to be ͑mostly͒ involved in the chirped control dynamics leading to enhanced fragmentation to CH 2 Cl + ͑X AЈ͒ +Br͑ 2 P 3/2 ͒. We propose that a wavepacket following or a time-delay resonance mechanism between the two-photon excited n x ͑Br, 22aЈ͒ → ͑2AЈ͒ repulsive surface and the three-photon near-resonant n x ͑Br, 22aЈ͒ → Rydberg͑AЈ͒ state of the neutral CH 2 BrCl molecule is responsible for the enhanced excitation of the n x ͑Br, 22aЈ͒ molecular orbital with up-chirped pulses. This leads to enhanced ionization to a configuration in the CH 2 BrCl + ͑X AЈ͒ continuum just above the dissociation limit of the CH 2 Cl + +Br͑ 2 P 3/2 ͒ channel, resulting in enhanced fragmentation.

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Quantum control of the yield of a chemical reaction

Cited by 65 publications

References 35 publications

Populations and coherence in femtosecond time resolved X-ray crystallography of the photoactive yellow protein

Populations and coherence in femtosecond time resolved X-ray crystallography of the photoactive yellow protein

Controlling dynamics in diatomic systems

Toward elucidating the mechanism of femtosecond pulse shaping control in photodynamics of molecules by velocity map photoelectron and ion imaging

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