相关论文: Effect of electron-phonon interaction range on lat…
We study the dynamics of a one-dimensional Bose gas at unit filling in both shallow and deep optical lattices and obtain the dynamic structure factor ${S(k,\omega)}$ by monitoring the linear response to a weak probe pulse. We introduce a…
In the first part of the thesis we consider the constraints of causality and unitarity for particles interacting via strictly finite-range interactions. We generalize Wigner's causality bound to the case of non-vanishing partial-wave…
The cross over from low to high carrier densities in a many-polaron system is studied in the framework of the one-dimensional spinless Holstein model, using unbiased numerical methods. Combining a novel quantum Monte Carlo approach and…
A dynamical mean-field theory of the small polaron problem is presented, which becomes exact in the limit of infinite dimensions. The ground state properties and the one-electron spectral function are obtained for a single electron…
I study the lattice dynamics and electron-phonon coupling in non-centrosymmetric quasi-one-dimensional K$_2$Cr$_3$As$_3$ using density functional theory based first principles calculations. The phonon dispersions show stable phonons without…
We study the properties of classical and quantum compacton chains by means of extensive numerical simulations. Such chains are strongly nonlinear and their classical dynamics remains chaotic at arbitrarily low energies. We show that the…
Tailoring the properties of correlated oxides is accomplished by chemical doping, pressure, temperature or magnetic field. Photoexcitation is a valid alternative to reach out-of-equilibrium states otherwise inaccessible. Here, we…
Bipolaron formation in a two-dimensional lattice with harmonic confinement, representing a simplified model for a quantum dot, is investigated by means of quantum Monte Carlo simulations. This method treats all interactions exactly and…
We present details of a continuous-time quantum Monte-Carlo algorithm for the screened Hubbard-Froehlich bipolaron. We simulate the bipolaron in one dimension with arbitrary interaction range in the presence of Coulomb repulsion, computing…
We present numerically exact solutions to the problem of a single electron interacting through a long range interaction with optical phonons in two and three dimensions. Comparisons are made with results for the standard Holstein model, and…
This study details the conditions under which strong-coupling perturbation theory can be applied to the molecular crystal model, a fundamental theoretical tool for analysis of the polaron properties. I show that lattice dimensionality and…
We report a theoretical study of the carrier relaxation in a quantum cascade laser (QCL) subjected to a strong magnetic field. Both the alloy (GaInAs) disorder effects and the Frohlich interaction are taken into account when the electron…
We study a highly imbalanced Fermi gas in a one-dimensional optical lattice from the polaronic point of view. The time-evolving block decimationg algorithm is used to calculate the ground state and dynamics of the system. We find…
The effect of electron-optical phonon interaction on the hydrogenic impurity binding energy in a cylindrical quantum wire is studied. By using Landau and Pekar variational method, the hamiltonian is separated into two parts which contain…
Applying a continuous-time quantum Monte-Carlo algorithm we calculate the exact coherent band dispersion and the density of states of a two dimensional lattice polaron in the region of parameters where any approximation might fail. We find…
An interacting electron-phonon system is considered within the Extended Holstein model at strong coupling regime and nonadiabatic approximation. It is assumed that screening of an electron-phonon interaction is due to the excess electrons…
Electron-phonon interaction and phonon frequencies of doped polar semiconductors are sensitive to long-range Coulomb forces and can be strongly affected by screening effects of free carriers, the latter changing significantly when…
One bottleneck of quantum Monte Carlo (QMC) simulation of strongly correlated electron systems lies at the scaling relation of computational complexity with respect to the system sizes. For generic lattice models of interacting fermions,…
We study the electric polarizability of a charged kaon from four-point functions in lattice QCD as an alternative to the background field method. Lattice four-point correlation functions are constructed from quark and gluon fields to be…
A new numerical method is proposed for determining the low-frequency dynamics of the charge carrier coupled to the deformable quantum lattice. As an example, the polaron band structure is calculated for the one-dimensional Holstein model.…