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Distinguishing Electronic and Vibronic Coherence in 2D Spectra by Their Temperature Dependence.

ABSTRACT: Long-lived oscillations in 2D spectra of chlorophylls are at the heart of an ongoing debate. Their physical origin is either a multipigment effect, such as excitonic coherence, or localized vibrations. We show how relative phase differences of diagonal- and cross-peak oscillations can distinguish between electronic and vibrational (vibronic) effects. While direct discrimination between the two scenarios is obscured when peaks overlap, their sensitivity to temperature provides a stronger argument. We show that vibrational (vibronic) oscillations change relative phase with temperature, while electronic oscillations are only weakly dependent. This highlights that studies of relative phase difference as a function of temperature provide a clear and easily accessible method to distinguish between vibrational and electronic coherences.

SUBMITTER: Perlik V

PROVIDER: S-EPMC3917822 | biostudies-other | 2014 Feb

REPOSITORIES: biostudies-other

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Distinguishing Electronic and Vibronic Coherence in 2D Spectra by Their Temperature Dependence.

Perlík Václav V Lincoln Craig C Sanda František F Hauer Jürgen J

The journal of physical chemistry letters 20140107 3

Long-lived oscillations in 2D spectra of chlorophylls are at the heart of an ongoing debate. Their physical origin is either a multipigment effect, such as excitonic coherence, or localized vibrations. We show how relative phase differences of diagonal- and cross-peak oscillations can distinguish between electronic and vibrational (vibronic) effects. While direct discrimination between the two scenarios is obscured when peaks overlap, their sensitivity to temperature provides a stronger argument ...[more]

PMID: 24527180

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