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D. Kilin

Publications and source records attributed to D. Kilin.

5 recordsLinked to original sources
arXiv2000

Electron Transfer in Porphyrin Complexes in Different Solvents

The electron transfer in different solvents is investigated for systems consisting of donor, bridge and acceptor. It is assumed that vibrational relaxation is much faster than the electron transfer. Electron transfer rates and final populations of the acceptor state are calculated numerically and in an approximate fashion analytically. In wide parameter regimes these solutions are in very good agreement. The theory is applied to the electron transfer in ${\rm H_2P-ZnP-Q}$ with free-base porphyrin (${\rm H_2P}$) being the donor, zinc porphyrin (${\rm ZnP}$) the bridge, and quinone (${\rm Q}$) the acceptor. It is shown that the electron transfer rates can be controlled efficiently by changing the energy of the bridging level which can be done by changing the solvent. The effect of the solvent is determined for different models.

cond-mat.soft↗
arXiv2000

Influence of phase-sensitive interaction on the decoherence process in molecular systems

The character of the interaction between an impurity vibrational mode and a heat bath leads to certain peculiarities in the relaxational dynamics of the excited states. We derive a non-Markovian equation of motion for the reduced density matrix of this system which is valid for initial, intermediate and kinetic stages of the relaxation. The linear phase-sensitive character of the interaction ensures the ultrafast disappearance of the quantum interference of the initially superpositional state and the effect of classical squeezing of the initially coherent state. On the other hand, the second power interaction induces a partial conservation of the quantum interference.

cond-mat.stat-mech↗
arXiv1999

Comparison of two models for bridge-assisted charge transfer

Based on the reduced density matrix method, we compare two different approaches to calculate the dynamics of the electron transfer in systems with donor, bridge, and acceptor. In the first approach a vibrational substructure is taken into account for each electronic state and the corresponding states are displaced along a common reaction coordinate. In the second approach it is assumed that vibrational relaxation is much faster than the electron transfer and therefore the states are modeled by electronic levels only. In both approaches the system is coupled to a bath of harmonic oscillators but the way of relaxation is quite different. The theory is applied to the electron transfer in ${\rm H_2P}-{\rm ZnP}-{\rm Q}$ with free-base porphyrin (${\rm H_2P}$) being the donor, zinc porphyrin (${\rm ZnP}$) being the bridge and quinone (${\rm Q}$) the acceptor. The parameters are chosen as similar as possible for both approaches and the quality of the agreement is discussed.

quant-ph↗
arXiv1999

Decoherence for phase-sensitive relaxation

The linear and quadratic interactions of an impurity vibrational mode coupled with a heat bath are investigated with a non-Markovian equation of motion for the reduced density matrix valid for the initial, intermediate and kinetic stages of relaxation. The evolution of the superpositional states is considered for all cases.

quant-ph↗