Unit:
Τομέας Φυσικής Συμπυκνωμένης ΎληςLibrary of the School of Science
Author:
Δημακογιάννη Μαργαρίτα
Dissertation committee:
Καθ. ΕΚΠΑ Γ. Π. Τριμπέρης (κύριος επιβλέπων), Αναπλ. Καθ. ΕΚΠΑ Α. Μαλάκης, Αναπλ. Καθ. ΕΚΠΑ Ι. Χατζηαγαπίου
Original Title:
Μελέτη της ηλεκτρικής αγωγιμότητας μονοδιαστάτων ατάκτων συστημάτων: εφαρμογή στο DNA και άλλες συναφείς δομές
Summary:
In the present thesis, we investigate the behaviour of the electrical
conductivity of one-dimensional disordered systems due to phonon-assisted
hopping of small polarons. We present a systematic theoretical study resulting
in analytical expressions for the temperature and the electric field dependence
of the conductivity of one dimensional disordered systems and the maximum
hopping distance, under the influence of low (ohmic behaviour) and moderate
(non-ohmic behaviour) electric fields. The role of correlation effects between
successive hops is revealed and a successful interpretation is given of the
experimentally observed temperature dependence of the electrical conductivity
of DNA samples. The experimentally observed field dependence of the
conductivity of one dimensional polymers is also successfully interpreted.
Furthermore, our theoretical analysis is generalized in order to investigate
the effect of electric fields of any intensity on the behaviour of the
electrical conductivity, and especially the effect of strong electric fields,
along with the temperature. Applying numerical calculations, the competitive
role of the electric field and the temperature is revealed. The influence of
the density of states and the localization length on the small polaron hopping
conductivity of 1D disordered systems for high and low temperatures is
presented.
Keywords:
Small Polarons, Hopping Conductivity, Electrical Conductivity, One-dimensional Disordered Systems , DNA
Number of references:
135
