Ladder-type "torsion-free" conducting polymers (e.g., polybenzimidazobenzophenanthroline (BBL)) can outperform "structurally distorted" donor-acceptor polymers (e.g., P(NDI2OD-T2)), in terms of conductivity and thermoelectric power factor. The polaron delocalization length is larger in BBL than in P(NDI2OD-T2), resulting in a higher measured polaron mobility. Structure-function relationships ar...

Several theoretical advances are presented, with the common theme of helping better understand and guide recent experiments in biophysical chemistry. In Chapter 2, I consider a recent criticism of the Jarzynski equality, notably that a breakdown in the connection between work and changes in the Hamiltonian for time-dependent systems causes the Jarzynski equality to produce unphysical results. I...

1.1. Setting of the problem. In this paper we are interested in the dynamics of a strongly coupled polaron. A polaron is a model of an electron in an ionic lattice interacting with its surrounding polarization field. In 1937 Fröhlich [8] proposed a quantum-mechanical Hamiltonian, given in (1.1) below, in order to describe the dynamics of a polaron. In this model the phonon field is treated as a...

Within a simple mean-field model (self-consistent Hartree approximation) we discuss the possibility of polaron formation on a molecular wire as a mechanism for negative differential resistance (NDR), switching, and/or hysteresis in the I-V characteristic of molecular junctions. This mechanism differs from earlier proposed mechanisms of charging and conformational change. The polaron model captu...

We prove theoretically the possibility of electric-field controlled polaron formation involving flexural (bending) modes in suspended carbon nanotubes. Upon increasing the field, the ground state of the system with a single extra electron undergoes a first-order phase transition between an extended state and a localized polaron state. For a common experimental setup, the threshold electric fiel...

The calculation of the radiative lifetime of a localized exciton confined in a quantum we11 is performed for CdTe/(Cd.hln)Te structure where the quasi-free exciton magnetic polaron can be formed. There is shown that the polaron induced squeezing of the in-plkne esciton localization radius leads to the increase of the lifetime. The lifetime dependence on the quantum well width is found to be alt...

By employing an adaptive time-dependent density-matrix-renormalization-group method, the spin-flip process of polarons is investigated in a polymer chain with magnetic impurities. Being driven by an external electric field, a polaron carrying both spin 1/2 and charge +/-e moves at a constant speed in the polymer chain. When the polaron passes through a specific site, which couples to a magnetic...