Quantum Beats and Phase Shifts in Two-Dimensional
Electronic Spectra of Zinc Naphthalocyanine Monomer and Aggregate
Ki-Hee Song
Munui Gu
Min-Seok Kim
Hyeok-Jun Kwon
Hanju Rhee
Hogyu Han
Minhaeng Cho
10.1021/acs.jpclett.5b02030.s001
https://acs.figshare.com/articles/journal_contribution/Quantum_Beats_and_Phase_Shifts_in_Two_Dimensional_Electronic_Spectra_of_Zinc_Naphthalocyanine_Monomer_and_Aggregate/2055192
The
origin of quantum coherence in two-dimensional (2D) electronic
spectra of molecular aggregates and light-harvesting complexes still
remains an open question. In particular, it could be challenging to
distinguish between electronic and vibrational coherences for a coupled
system, where both degrees of freedom can be simultaneously excited.
In this Letter, we examine quantum beats in the 2D spectra of zinc
naphthalocyanine (ZnNc) aggregate and monomer, and compare their characteristic
features in terms of the frequency and relative phase of diagonal
and off-diagonal amplitude oscillations. The long-lasting oscillating
components (>1 ps) at 600–700 cm<sup>–1</sup> observed
in both the aggregate and monomer are found to be attributed to the
vibrational coherence. The wide phase variations of the 2D spectral
amplitude oscillations are observed not just in the aggregate but
also in the monomer state. This suggests that the unusual 90°
phase shift may be attributed to neither quantum population-to-coherence
transfer nor vibronic exciton coupling.
2015-12-17 10:31:07
vibrational coherence
phase variations
monomer state
vibronic exciton
amplitude oscillations
quantum Beats
AggregateThe origin
zinc naphthalocyanine
quantum coherence
2 D
Phase Shifts
2 D spectra
Zinc Naphthalocyanine Monomer
vibrational coherences