Simulation of laser-induced coupled electron-nuclear dynamics and time-resolved harmonic spectra in complex systems

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.033408· OSTI ID:21541314

Lisinetskaya, Polina G; Mitric, Roland ^[1]

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1. Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)

We present a theoretical approach for the simulation of time-resolved harmonic spectra, including the effect of nuclear dynamics, which is applicable to complex systems involving many nuclear degrees of freedom. The method is based on the combination of our semiclassical field-induced surface hopping approach for the treatment of laser-induced nuclear dynamics with the time-dependent density functional theory for electron dynamics. We apply our method to the simulation of ultrafast nonadiabatic dynamics and time-resolved harmonic spectra in small silver clusters (Ag{sub 2} and Ag{sub 8}), which exhibit discrete molecularlike electronic transitions. We demonstrate that the harmonic signal is highly sensitive to the nuclear dynamics and thus can be used as a probe of coupled electron-nuclear dynamics, which is complementary to common pump-probe methods such as time-resolved photoelectron spectroscopy. Our simulations allowed us also to determine the mechanism and the time scale of nonradiative relaxation in the 'magic' Ag{sub 8} cluster and have provided a fundamental insight into ultrafast dynamics of metal nanoclusters in the size regime where 'each atom counts'. The excited-state dynamics of Ag{sub 8} involves an isomerization process from the initial structure with T{sub d} symmetry to the quadratic antiprism structure with D{sub 4d} symmetry which takes place on a time scale of {approx}3600 fs and is clearly identified in a time-resolved harmonic signal. Our theoretical approach is generally applicable for the prediction of time-resolved harmonic spectra in complex systems with many nuclear degrees freedom and should serve to stimulate new ultrafast experiments utilizing harmonic signals as a probe for nonadiabatic processes in molecular systems.

• OSTI ID: 21541314
• Journal Information: Physical Review. A, Vol. 83, Issue 3; Other Information: DOI: 10.1103/PhysRevA.83.033408; (c) 2011 American Institute of Physics; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ATOMS
DEGREES OF FREEDOM
DENSITY FUNCTIONAL METHOD
ELECTRONS
ISOMERIZATION
LASER RADIATION
NANOSTRUCTURES
PHOTOELECTRON SPECTROSCOPY
RELAXATION
SEMICLASSICAL APPROXIMATION
SIGNALS
SILVER
SIMULATION
SURFACES
SYMMETRY
TIME DEPENDENCE
TIME RESOLUTION
APPROXIMATIONS
CALCULATION METHODS
CHEMICAL REACTIONS
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
LEPTONS
METALS
RADIATIONS
RESOLUTION
SPECTROSCOPY
TIMING PROPERTIES
TRANSITION ELEMENTS
VARIATIONAL METHODS