title: Coherently-controlled two-dimensional spectroscopy: evidence for phase induced long-lived memory effects.
abstract: Using low-intensity phase-shaped excitation pulses we used two-dimensional (2D) electronic spectroscopy to follow the time dependence of the coherent correlations imposed on a solvated organic dye (Rhodamine 101 in methanol) at room temperature. Shaping of the excitation pulses strongly affects both the real and imaginary parts of the 2D-spectra, especially at small waiting times. In particular, the periodic phase modulation of the excitation pulses appears as a two-dimensional grid-like modulation in the correlation spectrum corresponding to the waiting time T = 0. By increasing the waiting time, this modulation quickly disappears in omega(t) space. However, it is still present in w, space even at very long waiting times (> or = 80 ps) where the inhomogeneous broadening is significantly reduced, and reaches its stationary value of approximately 16%. The resonant nature of this induced modulation at long waiting time allows us to conclude that phase shaping of the excitation induces a long-lived memory in solvated organic dyes that is associated with coherent population transfer.
authors.affiliation: Max 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
authors.forename: Valentyn I
authors.initials: VI
authors.lastname: Prokhorenko
authors.forename: Alexei
authors.initials: A
authors.lastname: Halpin
authors.forename: R J Dwayne
authors.initials: RJ
authors.lastname: Miller
mesh_terms: D000432:Methanol / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry*; D013057:Spectrum Analysis; D013997:Time Factors
chemical_list: D012235:Rhodamines; D000432:Methanol