Dissertation committee:
Αλέξανδρος Καρανίκας, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Φώτιος Διάκονος, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Peter Schmelcher, Καθηγητής, Institute of Laser Physics, Hamburg University
Κωνσταντίνος Σφέτσος, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Δημήτριος Φραντζεσκάκης, Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Jiannis K. Pachos, Καθηγητής, School of Physics and Astronomy, University of Leeds
Γεώργιος Διαμάντης, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Summary:
In the context of the present PhD thesis the structure and the inconsistencies of coherent-state path integrals were studied, and the proposed consistent methods were applied in the study of both closed and open quantum systems. For the study of bosonic and spin systems the proposed method was based on the inversion of the method of geometric quantization, and was constructed as an analytical map from the space of operators to the space of functions. For the study of fermionic systems the construction of the proposed method was based on the path integral quantization of Majorana fermion systems and was presented in the form of specific steps, leading to the consistent limit for both fermionic and spin-1/2 systems. The results were applied for the study of the dynamics of the one dimensional XY spin chain, in the presence of both a time-independent and a time-dependent magnetic field. Finally, the aforementioned methods were applied on the study of quantum systems coupled to a thermal bath.
