Observation of homogeneous vibrational dephasing in benzonitrile by ultrafast Raman echoes

Inaba, Ryoji; Tominaga, Kazuhiro; Tasumi, Mitsuo; Nelson, Keith A.; Yoshihara, Keitaro

doi:10.1016/0009-2614(93)85183-o

Cited by 84 publications

(42 citation statements)

References 11 publications

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“…By fitting the intensity data of the CARS signal to a single exponential function for the molecular vibrational modes at different wave-numbers, half of vibrational dephasing time T/2 can be worked out as shown in figure 17, which are consistent with the previously published data [43,[121][122][123] . But in a benzonitrile-methanol-ethanol mixture solution, the experimental results show that the influence of solvent on the property of solute is reflected not by the Raman peak position but by the variations of the vibrational dephasing times for different molecular vibrational modes.…”

Section: Ultra-broadband T-cars Spectroscopy With Sc Generated By Pcfsupporting

confidence: 83%

Ultra-Broadband Time-Resolved Coherent Anti-Stokes Raman Scattering Spectroscopy and Microscopy with Photonic Crystal Fiber Generated Supercontinuum

Niu¹,

Yin²

2012

Photonic Crystals - Innovative Systems, Lasers and Waveguides

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Section: Ultra-broadband T-cars Spectroscopy With Sc Generated By Pcfsupporting

confidence: 83%

Ultra-Broadband Time-Resolved Coherent Anti-Stokes Raman Scattering Spectroscopy and Microscopy with Photonic Crystal Fiber Generated Supercontinuum

Niu¹,

Yin²

2012

Photonic Crystals - Innovative Systems, Lasers and Waveguides

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“…The results obtained by our quantum FokkerPlanck approach displayed in Fig. 6 should be compared with seventh-order Raman echo experiments 12,47,48) or population relaxation and phase relaxation as was discussed in paper I and demonstrated also here. Similar observation have been made for the seventhorder 2D Raman response, where also an echo signal is predicted at T 1 = T 3 while the Raman echo in the LL model is observed at T 1 = 2T 3 .…”

Section: 50)mentioning

confidence: 55%

“…In the present paper, we demonstrate that this signal does show an echo for the exponentially correlated GaussianMarkovian noise. We will also show that fifth-order 2D spectroscopies, which are of great interest both theoretically and experimentally, [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] are sensitive to the correlation time of the noise.…”

Section: )mentioning

confidence: 99%

Two-Dimensional Spectroscopy for Harmonic Vibrational Modes with Nonlinear System-Bath Interactions. II. Gaussian-Markovian Case

2000

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The relaxation processes in a quantum system nonlinearly coupled to a harmonic GaussianMarkovian heat bath are investigated by the quantum Fokker-Planck equation in the hierarchy form. This model describes frequency fluctuations in the quantum system with an arbitrary correlation and thus bridges the gap between the wnian oscillator model and the chastic model by Anderson and Kubo. The effects of the finite correlation time and the system-bath coupling strength are studied for a harmonic model system by numerically integrating the equation of motion. The one-time correlation function of the system coordinate, which is measured in conventional Raman and infrared absorption experiments, already reflects the inhomogeneous character of the relaxation process. The finite correlation time of the frequency fluctuations, however, is directly evident only in the two-and three-time correlation function as probed by multidimensional spectroscopic techniques such as the Raman echo and the fifth-order 2D Raman experiment.KEYWORDS: 2D spectroscopy, Gaussian-Markovian, nonlinear system-bath interaction timeBro sto 4095 * E-mail: tanimura@ims.ac.jpJournal of the Physical Society of Japan Vol. 69, No. 12, December, 2000, pp. 4095-4106 §1. IntroductionThe interactions between the reacting molecules and their neighbors determine the reaction path and dynamics of virtually all chemical reactions in condensed phase systems. In order to better understand the basic chemical and biological processes various theoretical approaches such as ab initio calculations and molecular dynamics simulations have been taken. Optical spectroscopy is a very popular technique to study these processes experimentally: The position, width and shape of vibrational and vibronic resonances directly reflect the strength and dynamics of the most important molecular interactions. In spectroscopy, two relaxation processes are often distinguished:1-3) Energy relaxation is the process in which the excited electronic or vibrational states of a probe molecule (the system) return to the ground state by transferring the energy difference to the environmental molecules (the heat bath). Phase relaxation is caused by fluctuations of molecular energy levels, which destroys the phase coherence without energy dissipation. The lifetime of the excited state has then no meaning and is considered infinitely long.Theoretically, relaxation effects have been studied extensively by using a system-bath model, 2-4) such as the spin-Boson system, which consists of a two-level molecular system coupled to a harmonic oscillator bath. The spin-Boson Hamiltonian is expressed as 5) ators of the two-level system, b j and b + j are those of the jth bath oscillator. The interaction between the system and the bath is linear in the bath coordinates, but can be any function F (a, a + ) of the system coordinate. The heat bath acts as noise source, which induces fluctuations in the two-level system through the system-bath interaction. The noise is characterized by the noise correlation function...

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“…[25][26][27] Resonant third-order experiments such as IR photon echoes [28][29][30][31] and twodimensional IR [33][34][35] and nonresonant seventh-order experiments like the Raman echo [36][37][38] have been reported as well. Note that the 2D spectroscopy for electronically resonant experiments has also been proposed and has been carried out.…”

Section: -24)mentioning

confidence: 99%

Two-Dimensional Spectroscopy for Harmonic Vibrational Modes with Nonlinear System-Bath Interactions. I. Gaussian-White Case

Steffen

Tanimura

2000

J. Phys. Soc. Jpn.

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The quantum Fokker-Planck equation is derived for a system nonlinearly coupled to a harmonic oscillator bath. The system-bath interaction is assumed to be linear in the bath coordinates but quadratic in the system coordinate. The relaxation induced dynamics of a harmonic system are investigated by simulating the higher-order correlation functions of the Raman polarizability and the dipole moment, which represent the nonlinear optical responses of Raman or infrared spectroscopy. The 5th-order Raman response shows that, in addition to the frequency fluctuations induced by the bath, higher-order energy transfer between the system and bath plays a role. The nonlinearity of the system-bath interaction yields also an interesting feature in the 7th-order Raman echo or the 3rd-order infrared photon echo response: The calculations predict a finite signal for the case of a harmonic potential and a linear coordinate dependence of the polarizability or dipole while for linear system-bath coupling this response vanishes completely due to destructive interference of different Liouville space pathways.KEYWORDS: 2D Raman, 2D IR, quantum Fokker-Planck, nonlinear system-bath interaction monly assumes a certain functional form for the Hamiltonian of the medium, which allows for the derivation of closed form expressions that are fit to the experimental results. Such model approach, which is useful to understand the complex molecular interactions involved in optical processes, is complementary to more "realistic" approaches such as Molecular dynamics simulations. A typical example for this strategy is the Brownian oscillator model, which can be used to calculate, e.g., the first-order resonant IR response or the third-order offresonant Raman response. 5,8,9) Since the dipole moment or the polarizability is usually expanded in the power of molecular coordinate Q as μ(Q) = μ 1 Q + μ 2 Q 2 · · · or α(Q) = α 1 Q + α 2 Q 2 · · ·, the first-order IR or the third-order Raman onse in lowest order of Q is nothing but the two-time correlation functions of Brownian resp 3115 * E-mail: tanimura@ims.ac.jp rules for the transitions involved.To calculate the (non)linear optical response one com- §1. IntroductionFemtosecond nonlinear optical spectroscopies have proven to be valuable and versatile tools to obtain information on the dynamic characteristics of condensed phase systems.1-6) Usually, these experiments are described by a response function formalism, 5, 7) which is based on a perturbative expansion of the optical polarization in powers of the applied electric fields. For resonant spectroscopy, which is carried by the Infrared (IR) laser for molecular vibrational modes, the laser interaction is described by μE(t), where μ is the dipole moment of the system. Then, for example, the lowestorder signal is expressed by the dipole correlation function μ(t )μ(t) . For off-resonant Raman spectroscopy, in which resonance arises from a pair of laser pulses through Raman excitation processes, the laser interaction is described by αE 2 (t), where α is ...

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Observation of homogeneous vibrational dephasing in benzonitrile by ultrafast Raman echoes

Cited by 84 publications

References 11 publications

Ultra-Broadband Time-Resolved Coherent Anti-Stokes Raman Scattering Spectroscopy and Microscopy with Photonic Crystal Fiber Generated Supercontinuum

Ultra-Broadband Time-Resolved Coherent Anti-Stokes Raman Scattering Spectroscopy and Microscopy with Photonic Crystal Fiber Generated Supercontinuum

Two-Dimensional Spectroscopy for Harmonic Vibrational Modes with Nonlinear System-Bath Interactions. II. Gaussian-Markovian Case

Two-Dimensional Spectroscopy for Harmonic Vibrational Modes with Nonlinear System-Bath Interactions. I. Gaussian-White Case

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