title: High frequency vibrational modulations in two-dimensional electronic spectra and their resemblance to electronic coherence signatures.
abstract: In this work we analyze how nuclear coherences modulate diagonal and off-diagonal peaks in two-dimensional electronic spectroscopy. 2D electronic spectra of pinacyanol chloride are measured with 8 fs pulses, which allows coherent excitation of the 1300 cm(-1) vibrational mode. The 2D spectrum reveals both diagonal and off-diagonal peaks related to the vibrational mode. On early time scales, up to 30 fs, coherent dynamics give rise to oscillations in the amplitudes, positions, and shapes of the peaks in the 2D spectrum. We find an anticorrelation between the amplitude and the diagonal width of the two diagonal peaks. The measured data are reproduced with a model incorporating a high frequency mode coupled to an electronic two-level-system. Our results show that these anticorrelated oscillations occur for vibrational wavepackets and not exclusively for electronic coherences as has been assumed previously.
authors.affiliation: Electronic Properties of Materials, Faculty of Physics, University of Vienna, Strudlhofgasse 4, 1090 Vienna, Austria.
authors.forename: N
authors.initials: N
authors.lastname: Christensson
authors.forename: F
authors.initials: F
authors.lastname: Milota
authors.forename: J
authors.initials: J
authors.lastname: Hauer
authors.forename: J
authors.initials: J
authors.lastname: Sperling
authors.forename: O
authors.initials: O
authors.lastname: Bixner
authors.forename: A
authors.initials: A
authors.lastname: Nemeth
authors.forename: H F
authors.initials: HF
authors.lastname: Kauffmann
mesh_terms: D002232:Carbocyanines / Q000737:chemistry*; D004583:Electrons; D011789:Quantum Theory; D013997:Time Factors; D014732:Vibration
chemical_list: D002232:Carbocyanines; C019071:quinaldine blue