Time Resolved Spectroscopy

Time-resolved spectroscopy is the name given to a set of experimental tools that allow for the measurement of time-resolved quantities. A frequently used technique is pump-probe spectroscopies where a very short laser pulse is used to excite the system, and then another pulse is used to "read" the excited-state. Common examples are the study of photo-induced chemical reactions, time-resolved infra-red or fluorescence spectroscopy.

In this Beamline we will deal not only with this kind of experiment, but with others in what may be defined as "time-dependent theoretical spectroscopies". By this we mean all quantities that can not be calculated by making straightforward use of the linear-response formalism in frequency space, either because the processes are inherently timedependent, as in time-resolved spectroscopy, or because we are dealing with processes that involve strong interactions between the probe and the system. Examples of the latter are (strongly) nonlinear optics, attosecond dynamics, ionisation yields, high-harmonic generation, and quantumcontrol of electronic/ionic processes.

What do we calculate?

• Time-resolved excitations, photoinduced chemical reactions, time-resolved fluorescence spectroscopy.
• Strongly non-linear optics, attosecond dynamics, ionization yields, high-harmonic generation.
• Quantum-control of electronic/ionic processes.

Which systems do we study?

• Molecules and Clusters.

Methodolody

• Time Dependent Density Functional Theory.
• Code: Octopus.

How to use ETSF services?

• Introduction Package for New Users.

Beamline Coordinator

Dr. Alberto Castro

Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Zaragoza
acastro [at] bifi [dot] es

References

• Time-dependent electron localization function,
  T. Burnus, M.A.L. Marques, and E.K.U. Gross, Phys. Rev. A R71, 10501 (2005).
• Excited states dynamics in time-dependent density functional theory: high-field molecular dissociation and harmonic generation,
  A. Castro, M.A.L. Marques, J.A. Alonso, G.F. Bertsch, and A. Rubio, Eur. Phys. J. D 28, 211 (2004).
• Optimal laser control of double quantum dots,
  E. Räsänen, A. Castro, J. Werschnik, A. Rubio and E. K. U. Gross, Phys. Rev. B 77, 085324 (2008).
• Control of Quantum Rings by Terahertz Laser Pulses,
  E. Räsänen, A. Castro, J. Werschnik, A. Rubio and E. K. U. Gross, Phys. Rev. Lett. 98, 157404 (2007).
• Strong-field ionization dynamics of a model H-2 molecule,
  M. Lein, T. Kreibich, E.K.U. Gross and V. Engel, Phys. Rev. A 65, 033403 (2002).