Polariton Induced Conical Intersection and Berry Phase

We investigate the Polariton induced conical intersection (PICI) created from coupling a diatomicmolecule with the quantized photon mode inside an optical cavity, and the corresponding BerryPhase effects. We use the rigorous Pauli-Fierz Hamiltonian to describe the quantum light-matterinteractions between a LiF molecule and the cavity, and exact quantum propagation to investigatethe polariton quantum dynamics. The molecular rotations relative to the cavity polarization directionplay a role as the tuning mode of the PICI, resulting in an effective CI even within a diatomic molecule.To clearly demonstrate the dynamical effects of the Berry phase, we construct two additional modelsthat have the same Born-Oppenheimer surface, but the effects of the geometric phase are removed.We find that when the initial wavefunction is placed in the lower polaritonic surface, the Berryphase causes aπphase-shift in the wavefunction after the encirclement around the CI, indicatedfrom the nuclear probability distribution. On the other hand, when the initial wavefunction is placedin the upper polaritonic surface, the geometric phase significantly influences the couplings betweenpolaritonic states and therefore, the population dynamics between them. These BP effects are furtherdemonstrated through the photo-fragment angular distribution. PICI created from the quantizedradiation field has the promise to open up new possibilities to modulate photochemical reactivities.

Polariton Induced Conical Intersection and Berry Phase

We investigate the Polariton induced conical intersection (PICI) created from coupling a diatomicmolecule with the quantized photon mode inside an optical cavity, and the corresponding BerryPhase effects. We use the rigorous Pauli-Fierz Hamiltonian to describe the quantum light-matterinteractions between a LiF molecule and the cavity, and exact quantum propagation to investigatethe polariton quantum dynamics. The molecular rotations relative to the cavity polarization directionplay a role as the tuning mode of the PICI, resulting in an effective CI even within a diatomic molecule.To clearly demonstrate the dynamical effects of the Berry phase, we construct two additional modelsthat have the same Born-Oppenheimer surface, but the effects of the geometric phase are removed.We find that when the initial wavefunction is placed in the lower polaritonic surface, the Berryphase causes aπphase-shift in the wavefunction after the encirclement around the CI, indicatedfrom the nuclear probability distribution. On the other hand, when the initial wavefunction is placedin the upper polaritonic surface, the geometric phase significantly influences the couplings betweenpolaritonic states and therefore, the population dynamics between them. These BP effects are furtherdemonstrated through the photo-fragment angular distribution. PICI created from the quantizedradiation field has the promise to open up new possibilities to modulate photochemical reactivities.

Dynamics of proton, ion, molecule, and crystal lattice in functional molecular assemblies

Dynamic molecular processes, such as short- or long-range proton (H+) and ion (M+) motions, and molecular rotations in electrical conducting and magnetic molecular assembly enable to fabricate the electron –...

Harnessing molecular rotations in plastic crystals: a holistic view for crystal engineering of adaptive soft materials

This review highlights the exceptional properties of plastic crystals, their expanding scope in materials sciences and plenty of opportunities for designing new mechanically soft functional crystals.

Низкочастотные молекулярные отклики в жидкости при регистрации сверхбыстрого оптического эффекта Керра

Low-frequency molecular rotations recorded in a region of 0–150 cm^–1 with a high “signal/noise” ratio in the ultrafast optical Kerr effect (OKE), which is a third-order nonlinear optical response upon nonresonant excitation of a liquid by femtosecond laser pulses, are analyzed in detail. It is shown that the reduced Raman spectral density (RSD) derived from experimental data using the well-known deconvolution procedure is ambiguous due to the problem of separating the orientational and librational contributions to the total OKE signal. This fact significantly limits the reliability of information derived about molecular motions in a liquid. For the example of an ultrafast OKE in benzonitrile, it is shown that, in the range of 0–300 fs, rotational responses cannot be considered independent, and the application of a number of additional criteria resulting from the assumption of their correlation allows this ambiguity in deriving the RSD function from experimental data to be removed.

Pressure-induced emission enhancement in hexaphenylsilole: a computational study

The pressure-induced emission enhancement in hexaphenylsilole is a consequence of restricted low-frequency molecular rotations. Excessive pressurization over 5.06 GPa hampers the high-frequency molecular vibrations without further limitation of molecular rotations.

Solitons in discrete linear chains of chiral smectic liquid crystals with competing interactions

Chiral liquid crystals exhibit in-plane spontaneous polarizations, however, in their smectic (Sm) phase the primary-order parameter is the tilt vector associated with molecular rotations around the long axis parallel to the molecular directors. These molecular rotations can lead to several distinct phases among which an incommensurate order with a domain-wall texture is referred to as soliton. In this study, the formation of domain walls in smectic chiral (SmC) liquid crystals is analyzed, with emphasis on the competition between an Ising-like symmetric intermolecular interaction, an anti-symmetric intermolecular interaction due to molecular chirality and an applied in-plane electric field. It is found that the anti-symmetric intermolecular interaction increases the width of kink structures in the domain wall at moderate intensity of the y-component of the applied in-plane electric field. Increasing the x-component of the electric field creates unstable condition for soliton formation irrespective of magnitudes of the symmetric and chiral intermolecular interactions. The stability condition for single-kink structures in the discrete molecular chain is discussed, by estimating the Peierls stress experienced by the single-kink soliton. Results suggest that chirality lowers the Peierls–Nabarro barrier, hence increasing the lifetime of single-kink structures in the discrete medium.