Polaron dynamics in a two-dimensional Holstein-Peierls system.

A Theoretical Study of Charge

The main objective of this thesis is to provide a deeper understanding of the charge transport phenomena occuring in molecular crystals. The focus is on the stability and the dynamics of the polaron as the charge carrier. To achieve this goal, a series of numerical calculations are performed using the semi-emprical "Holstien-Peierls" model. The model considers both intra(Holstein) and inter(Pei...

Polaron dynamics in a two-dimensional anharmonic Holstein model

Theoretical Description of the Electron-lattice Interaction in Molecular and Magnetic Crystals

Electron-lattice interactions are often considered not to play a major role in material’s properties as they are assumed to be small, the second-order effects. This study, however, shows the importance of taking these effects into account in the simulations. My results demonstrate the impact of the electron-lattice interaction on the physics of the material and our understanding from it. One wa...

شبیه سازی ذوب سیستمهای دو بعدی

  The study of a two-dimensional (2-D) system started nearly half a century ago when Peierls and Landau showed the lack of long range translational order in a two-dimensional solid. In 1968, Mermin proved that despite the absence of long range translational order. Two-dimensional solids can still exhibit a different kind of long range bond orientation. During the last decade, fascinating theori...

Polaron band formation in the Holstein model

We present numerical exact results for the polaronic band structure of the Holstein molecular crystal model in one and two dimensions. The use of direct Lanczos diagonalization technique, preserving the full dynamics and quantum nature of phonons, allows us to analyze in detail the renormalization of both quasiparticle bandwidth and dispersion by the electron–phonon interaction. For the two–dim...