Polaritonic molecular clock for all-optical ultrafast imaging of wavepacket dynamics without probe pulses

Silva, R. E. F.; Pino, Javier del; García‐Vidal, F. J.; Feist, Johannes

doi:10.1038/s41467-020-15196-x

Cited by 35 publications

(62 citation statements)

References 60 publications

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“…We observe that the avoided crossings are located at the edges of the oscillation coordinate q osc , where the WP velocity approaches zero as it reverts its motion. Coherently with the study by Silva et al, 60 we then see that a more efficient transfer to | S 0 , 1⟩ is obtained when the WP moves slowly and spends more time in the coupled region; that is, its motion tends to follow the adiabatic behavior introduced above. The pseudoharmonic oscillation around the S 2 min is also responsible for the stair-like population dynamics of the | S 2 , 0⟩ state, presented in Figure 2 c. In particular, the transfer occurs only when the WP hits the resonant region sitting at the limit of q osc .…”

supporting

confidence: 85%

Photoprotecting Uracil by Coupling with Lossy Nanocavities

Felicetti

Fregoni

Schnappinger

et al. 2020

J. Phys. Chem. Lett.

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We analyze how the photorelaxation dynamics of a molecule can be controlled by modifying its electromagnetic environment using a nanocavity mode. In particular, we consider the photorelaxation of the RNA nucleobase uracil, which is the natural mechanism to prevent photodamage. In our theoretical work, we identify the operative conditions in which strong coupling with the cavity mode can open an efficient photoprotective channel, resulting in a relaxation dynamics twice as fast as the natural one. We rely on a state-of-the-art chemically detailed molecular model and a non-Hermitian Hamiltonian propagation approach to perform full-quantum simulations of the system dissipative dynamics. By focusing on the photon decay, our analysis unveils the active role played by cavity-induced dissipative processes in modifying chemical reaction rates, in the context of molecular polaritonics. Remarkably, we find that the photorelaxation efficiency is maximized when an optimal trade-off between light–matter coupling strength and photon decay rate is satisfied. This result is in contrast with the common intuition that increasing the quality factor of nanocavities and plasmonic devices improves their performance. Finally, we use a detailed model of a metal nanoparticle to show that the speedup of the uracil relaxation could be observed via coupling with a nanosphere pseudomode, without requiring the implementation of complex nanophotonic structures.

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supporting

confidence: 85%

Photoprotecting Uracil by Coupling with Lossy Nanocavities

Felicetti

Fregoni

Schnappinger

et al. 2020

J. Phys. Chem. Lett.

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“…Although, in both studied situations, emission occurs quite obviously whenever the nuclear wavepacket is found at a geometry resonant with the cavity, in Ref. 36 no SR enhancement in the emission rate is observed. The reason for this is the fact that the laser pulse excites the system in the perturbative, one-photon regime, in which SR cannot take place.…”

Section: B Pyrazine Ensemble Coupled To the Cavity Via The S 0 -S 2 mentioning

confidence: 85%

“…Recently, it has been shown theoretically that the time-dependent emission of a low-Q cavity can be used to track the intramolecular dynamics after excitation of the ensemble. 36 It was demonstrated that the motion of the nuclear density in and out of the resonance region can be followed through the emission characteristics, as an emission requires the population of polaritonic modes, which are local probes of the molecular configuration. Although, in both studied situations, emission occurs quite obviously whenever the nuclear wavepacket is found at a geometry resonant with the cavity, in Ref.…”

Section: B Pyrazine Ensemble Coupled To the Cavity Via The S 0 -S 2 mentioning

confidence: 99%

Multiphoton Excitation of Organic Molecules in a Cavity – Superradiance as a Measure of Coherence

Ulusoy¹,

Gomez²,

Vendrell³

2020

Preprint

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<div>Coherent excitation of a molecular ensemble coupled to a common radiation mode can lead to the collective emission of radiation known as superradiance. This collective emission only occurs if there is an entanglement between the molecules in their ground and excited state and can therefore serve as a macroscopic measure of coherence in the ensemble. Reported here are wave packet propagations for various pyrazine models of increasing complexity and molecular ensembles thereof. We show that ensemble coherence upon photoexcitation can prevail up to relatively long time scales, although the effect can diminish quickly with increasing ensemble size. Coherence can also build up over time and even reemerge after the molecules have passed through a conical intersection. The effect of the pump-pulse characteristics on the collective response of the molecular ensemble is also studied. A broad-band pulse imprints a large amount of initial coherence to the system, as compared to a longer pulse with a smaller spread in the frequency domain. However, the differential effects arising from a different pulse duration and coherent bandwidth become less prominent if the emission of light from the ensemble takes place after a non-adiabatic decay process.</div>

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“…This is because, soon after its generation, the exciton vibrational wavepacket remains in the vicinity of the Franck–Condon region before exploring the potential energy surface of the excited state. 61 Hence, within a very short time scale, vibrations do not play any role yet and the TLS model describes the molecular decay. This time scale, τ 1 , can be estimated as a fraction of the period associated with the RC harmonic motion, T RC = 2π/ω RC .…”

Section: Resultsmentioning

confidence: 99%

Impact of Vibrational Modes in the Plasmonic Purcell Effect of Organic Molecules

et al. 2020

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By means of quantum tensor network calculations, we investigate the large Purcell effect experienced by an organic molecule placed in the vicinity of a plasmonic nanostructure. In particular, we consider a donor-π bridge-acceptor dye at the gap of two Ag nanospheres. Our theoretical approach allows for a realistic description of the continua of both molecular vibrations and optical nanocavity modes. We analyze both the ultrafast exciton dynamics in the large Purcell enhancement regime and the corresponding emission spectrum, showing that these magnitudes are not accurately represented by the simplified models used up to date. Specifically, both the two-level system model and the single vibrational mode model can only reproduce the dynamics over short time scales, whereas the Fermi’s golden rule approach accounts only for the behavior at very long times. We demonstrate that including the whole set of vibrational modes is necessary to capture most of the dynamics and the corresponding spectrum. Moreover, by disentangling the coupling of the molecule to radiative and nonradiative plasmonic modes, we also shed light into the quenching phenomenology taking place in the system.

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Polaritonic molecular clock for all-optical ultrafast imaging of wavepacket dynamics without probe pulses

Cited by 35 publications

References 60 publications

Photoprotecting Uracil by Coupling with Lossy Nanocavities

Photoprotecting Uracil by Coupling with Lossy Nanocavities

Multiphoton Excitation of Organic Molecules in a Cavity – Superradiance as a Measure of Coherence

Impact of Vibrational Modes in the Plasmonic Purcell Effect of Organic Molecules

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