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Published on: November 11, 2013
Coherently-controlled two-dimensional spectroscopy: evidence for phase induced long-lived memory effects.
Valentyn I Prokhorenko1, Alexei Halpin, R J Dwayne Miller
1Max Planck Research Department for Structural Dynamics, Department of Physics, University of Hamburg, Center of Free Electron Laser Science, DESY, Notkestr. 85, 22607 Hamburg, Germany. valentyn.prokhorenko@mpsd.cfel.de
Faraday Discussions
|March 29, 2012
Summary
Phase-shaped excitation pulses reveal long-lived memory in organic dyes. This coherent population transfer, observed via two-dimensional electronic spectroscopy, persists for over 80 ps.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Materials Science
Background:
- Coherent correlations in solvated organic dyes are crucial for understanding light-matter interactions.
- Two-dimensional electronic spectroscopy (2D-ES) is a powerful technique for probing ultrafast dynamics.
Purpose of the Study:
- To investigate the impact of phase-shaped excitation pulses on coherent correlations in Rhodamine 101 in methanol.
- To determine the time dependence of these correlations at room temperature.
Main Methods:
- Utilized low-intensity phase-shaped excitation pulses.
- Employed two-dimensional electronic spectroscopy (2D-ES) to monitor time-dependent coherent correlations.
- Analyzed Rhodamine 101 in methanol at room temperature.
Main Results:
- Phase shaping significantly altered both real and imaginary parts of the 2D-spectra, particularly at short waiting times.
- A grid-like modulation, corresponding to the excitation pulse's phase modulation, was observed at T=0.
- This modulation persisted in the w, space for >80 ps, reaching a stationary value of ~16%.
Conclusions:
- Phase shaping of excitation pulses induces a long-lived memory in solvated organic dyes.
- This memory is linked to coherent population transfer.
- The observed modulation's resonant nature at long waiting times supports this conclusion.
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