Control of Chemical Reactions by Feedback-Optimized Phase-Shaped Femtosecond Laser Pulses

Assion, A.; Baumert, Thomas; Bergt, M.; Brixner, Tobias; Kiefer, Boris; Seyfried, V.; Strehle, M.; Gerber, G.

doi:10.1126/science.282.5390.919

Cited by 1,566 publications

(881 citation statements)

References 28 publications

Supporting

Mentioning

858

Contrasting

Unclassified

Order By: Relevance

“…The answers carry important consequences for scientific dreams and visions, e.g. to create synthetic atomic quantum systems and exotic molecules beyond the reaches of traditional chemistry by ultrafast temporally tailored light fields 29 .…”

mentioning

confidence: 99%

Reconstruction and control of a time-dependent two-electron wave packet

Ott

Kaldun

Argenti

et al. 2014

Nature

277

218

View full text Add to dashboard Cite

Esta es la versión de autor del artículo publicado en: This is an author produced version of a paper published in: The concerted motion of two or more bound electrons governs atomic 1 and molecular 2,3 non-equilibrium processes and chemical reactions. It is thus a long-standing scientific dream to measure and control the dynamics of two bound and correlated electrons in the quantum regime. At least two active electrons and a nucleus are required to address such quantum three-body problem 4 for which analytical solutions do not exist, a condition that is met in the helium atom. While attosecond dynamics were previously observed for singleactive electron/hole cases 5-7 , such time-resolved observation of two-electron motion thus far remained an unaccomplished challenge. Here, we measure a 1.2-femtosecond quantum beat among low-lying doubly-excited states in helium and use it to reconstruct a correlated two-electron wave packet. Our experimental method combines attosecond transientabsorption spectroscopy 5,7-9 at unprecedented high spectral resolution (20 meV s.d. near 60 eV) with an intensity-tuneable visible laser field to couple 10-12 the quantum states from the weak-field to the strong-coupling regime. Employing the Fano resonance as a phasesensitive quantum interferometer 13 , we demonstrate the coherent control of two correlated electrons, which form the basis of most covalent molecular bonds in nature. As we show, such multi-dimensional spectroscopy experiments provide benchmark data for testing fundamental few-body quantum-dynamics theory. They also light a route for site-specific measurement and control of metastable electronic transition states that are at the heart of fundamental reactions in chemistry and biology.Electrons are bound to atoms and molecules by the Coulomb force of the nuclei. Moving between atoms, they form the basis of the molecular bond. The same Coulomb force, however, acts repulsively between the electrons. This electron-electron interaction represents a major challenge in the understanding and modelling of atomic and molecular states, their structure and in particular their dynamics 2,3,14 . Here, we focus on the 1 P sp 2,n+ series 15 of doubly-excited states in helium below the N = 2 ionization threshold. They are excited by a single-photon transition from the 1 S 1s 2 ground state by the promotion of both electrons to at least principal quantum number n = 2. The states autoionize due to electron-electron interaction and their spectroscopic signature manifests as asymmetric non-Lorentzian line shapes. The latter were first observed in the 1930s 16 and attributed 17 , by Ugo Fano, to the quantum interference of bound states with the continuum to which they are coupled (Fig. 1c,d). The coupling is described by the configuration interaction V CI with the single-ionization continuum |1s,p, where one electron is in the 1s ground state and the other one is in the continuum with kinetic energy . The magnitude of V CI determines the lifetimes of the transiently bound states. In our case,...

show abstract

mentioning

confidence: 99%

Reconstruction and control of a time-dependent two-electron wave packet

Ott

Kaldun

Argenti

et al. 2014

Nature

277

218

View full text Add to dashboard Cite

show abstract

“…An alternative approach based on the use of the combination of pulse shaping techniques [12] with adaptive feedback learning loops (closed loop) was suggested [13] for the case when the underlying potential surfaces are unknown. Implementations of this technique demonstrate the optimization of almost any conceivable physical quantity [14][15][16][17][18][19][20][21][22][23][24][25][26]. However, it is not clear whether this methodology is suitable to extract the underlying physical mechanism from the electrical fields obtained during the optimization process.…”

Section: Introductionmentioning

confidence: 99%

Strong field quantum control by selective population of dressed states

Wollenhaupt

Präkelt

Sarpe-Tudoran

et al. 2005

J. Opt. B: Quantum Semiclass. Opt.

View full text Add to dashboard Cite

We study the dynamics of potassium atoms in intense laser fields using femtosecond phase-locked pulse pairs in order to extract physical mechanisms of strong field quantum control. The structure of the Autler-Townes (AT) doublet in the photoelectron spectra is measured to analyse transient processes. The analysis shows that the physical mechanism is based on the selective population of dressed states (SPODS). Experimental results of closed loop optimization of SPODS are presented in addition. Applications to decoherence measurements with implications for quantum information are also proposed.

show abstract

“…Among the first demonstrations of this method were the optimization of the excited state population of a laser dye by Bardeen et al [45] and the automated compression of femtosecond laser pulses [44,[46][47][48]. Since then, the dissociation of molecules in the gas phase [49][50][51][52], energy transfer in large biomolecular molecules [53], selective excitation of different vibrational modes [54,55] and the control of the geometrical rearrangement in the liquid phase [56] and many other problems have been successfully controlled.…”

Section: Adaptive Quantum Controlmentioning

confidence: 99%