Unit:
Κατεύθυνση Πυρηνική Φυσική και Φυσική Στοιχειωδών ΣωματιδίωνLibrary of the School of Science
Author:
Thabet Andreas-Naouman
Supervisors info:
Φώτιος Διάκονος, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Original Title:
Ising model with designed next neighbour couplings
Translated title:
Ising model with designed next neighbour couplings
Summary:
In the standard Ising Model, what determines how energy and magnetisation behave at equilibrium is the coupling between neighbouring spins. Usually, the ferromagnetic phase transition is studied in Ising lattices with uniform (positive) coupling. Nevertheless, it is interesting to consider Ising lattices with non-uniform couplings either random (spin glasses) or following a specific pattern. In the present thesis we study the case of couplings following the pattern of a Fibonacci word, suitably modelled to preserve reciprocity. We explore the basic phenomenological characteristics of the model as we vary the ratio of the strength of the letters in the Fibonacci alphabet. We observe an anomalous double peak behaviour of the specific heat as a function of temperature. The position of the lowest energy peak is controlled by the letter strength ratio. Additional suitable models have been proposed and investigated for the interpretation of the observed phenomenological
characteristics.
Main subject category:
Science
Keywords:
statistical physics, simulation, python, Ising model, magnetisation, heat capacity, fibonacci, shottky anomaly
File:
File access is restricted until 2025-03-16.
Ising model with designed next neighbour couplings.pdf
16 MB
File access is restricted until 2025-03-16.
