Quantum dynamics and spectroscopy of dihalogens in solid matrices. II. Theoretical aspects and G-MCTDH simulations of time-resolved coherent Raman spectra of Schrödinger cat states of the embedded ${\mathrm{I}}_2\mathrm{K}{\mathrm{r}}_{18}$ cluster

Abstract

This companion paper to [D. Picconi et al., J. Chem. Phys. 150 (2019)] presents quantum dynamical simulations, using the Gaussian-based multiconfigurational time-dependent Hartree (G-MCTDH) method, of time-resolved coherent Raman four-wave-mixing spectroscopic experiments for the iodine molecule embedded in a cryogenic crystal krypton matrix. These experiments monitor the time-evolving vibrational coherence between two wave packets created in a quantum superposition (i. e. a 'Schrödinger cat state') by a pair of pump pulses which induce electronic $B{}^3{\Pi }_u\left(0^{+}\right)⟵X{}^1{\Sigma }_g^{+}$ transitions. A theoretical description of the spectroscopic measurement is developed, which elucidates the connection between the nonlinear signals and the wave packet coherence. The analysis provides an effective means to simulate the spectra for several different optical conditions with a minimum number of quantum dynamical propagations. The G-MCTDH method is used to calculate and interpret the time-resolved coherent Raman spectra of two selected initial superpositions for a ${\mathrm{I}}_2\mathrm{K}{\mathrm{r}}_{18}$ cluster embedded in a frozen Kr cage. The time- and frequency-dependent signals carry information about the molecular mechanisms of dissipation and decoherence, which involve vibrational energy transfer to the stretching mode of the four 'belt' Kr atoms. The details of these processes and the number of active solvent modes depend in a non-trivial way on the specific initial superposition.

References in corpus (3)

• Wigner functions, squeezing properties and slow decoherence of atomic Schrodinger cats
• Simplified Approach to the Mixed Time-averaging Semiclassical Initial Value Representation for the Calculation of Dense Vibrational Spectra
• Quantum dynamics and spectroscopy of dihalogens in solid matrices. I. Efficient simulation of the photodynamics of the embedded ${\mathrm{I}}_2\mathrm{K}{\mathrm{r}}_{18}$ cluster using the G-MCTDH method

Cited by in corpus (4)

• Finite-temperature, anharmonicity, and Duschinsky effects on the two-dimensional electronic spectra from ab initio thermo-field Gaussian wavepacket dynamics
• On-the-fly ab initio semiclassical evaluation of third-order response functions for two-dimensional electronic spectroscopy
• Semiclassical vibrational spectroscopy with Hessian databases
• Quantum dynamics and spectroscopy of dihalogens in solid matrices. I. Efficient simulation of the photodynamics of the embedded ${\mathrm{I}}_2\mathrm{K}{\mathrm{r}}_{18}$ cluster using the G-MCTDH method