The absorption of large bipolarons is investigated using the path-integral method. The response of a bipolaron to an external electromagnetic field is derived in the framework of the memory function approach. The bipolaron optical absorption spectrum consists of a series of relatively narrow peaks. The peculiarities of the bipolaron optical absorption as a function of the frequency of the elect...

We present a theory for spin-polarized transport through a generic organic polymer connected to ferromagnetic leads with arbitrary angle θ between their magnetization directions, taking into account the polaron and bipolaron states as effective charge and spin carriers. Within a diffusive description of polaron-bipolaron transport including polaron-bipolaron conversion, we find that the bipolar...

Large-radius translation invariant (TI) bipolarons are considered in a one-dimensional Holstein molecular chain. Criteria of their stability are obtained. The energy of a translation invariant bipolaron is shown to be lower than that of a bipolaron with broken symmetry. The results obtained are applied to the problem of superconductivity in 1D-systems. It is shown that TI-bipolaron mechanism of...

Effects of interchain interaction on the polaron-bipolaron transition on conjugated polymer are investigated. We use the Su-Schrieffer-Heeger model combined with the Pariser-Parr-Pople model modified to include interchain interaction, and an external electric field. We study the dynamics within the Time-Dependent Unrestricted HartreeFock approximation. We find that removing an electron from int...

The bound states of two electrons in the adiabatic Holstein-Hubbard model are studied numerically in one and two dimensions from the anticontinuous limit. This model involves a competition between a local electron-phonon coupling (with a classical lattice) which tends to form pairs of electrons and the repulsive Hubbard interaction U ≥ 0 which tends to break them. In 1D, the ground-state always...

• This is a pre-print. The denitive version: LEE, ALEXANDROV and LIANG, 2003. Lorenz number in high Tc superconductors: evidence for bipolarons.

By using the Su-Schrieffer-Heeger model modified to include electron-electron interactions, the Brazovskii-Kirova symmetry breaking term and an external electric field, we investigate the scattering process between a negative and a positive bipolaron in a system composed of two coupled polymer chains. Our results show that the Coulomb interactions do not favor the bipolaron recombination. In th...

We compute the properties of singlet and triplet bipolarons on two-dimensional lattices using the continuous time quantum Monte Carlo algorithm. Properties of the bipolaron including the total energy, inverse mass, bipolaron radius and number of phonons associated with the bipolaron demonstrate the qualitative difference between models of electron phonon interaction with longrange interaction (...

We investigate the pathways of polaron and bipolaron transports in DNA double strands with an extended Su-Schrieffer-Heeger model involving the effects of solvent polarization. We find that the long-range transport of polaron/bipolaron under high electric field at low temperature is the field-facilitated sequential tunneling through spatial-disordered potential barriers via multiple intrastrand...

This is a brief report of the author’s talk on some of bipolaron problems in the light of mathematical physics.