The nature of the phonon eigenstates in quasiperiodic chains ( the role of Fibonacci lattices )
محل انتشار: مجله پژوهش فیزیک ایران، دوره: 5، شماره: 2
سال انتشار: 1384
نوع سند: مقاله ژورنالی
زبان: انگلیسی
مشاهده: 363
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شناسه ملی سند علمی:
JR_PSI-5-2_008
تاریخ نمایه سازی: 30 دی 1397
چکیده مقاله:
Using the forced oscillator method (FOM) and the transfer-matrix technique, we numerically investigate the nature of the phonon states and the wave propagation, in the presence of an external force, in the chains composed of Fibonacci lattices of type site, bond and mixing models, as the quasiperiodic systems. Calculating the Lyapunov exponent and the participation ratio, we also study the localization properties of phonon eigenstates in these chains. The focus is on the significant relationship between the transmission spectra and the nature of the phonon states. Our results show that in the presence of the Fibonacci lattices, at low and medium frequencies the spectra of the quasiperiodic systems are not much different from those of the periodic ones and the corresponding phonon eigenstates are extended. However, the numerical results of the calculations of the trans inverse Lyapunov exponent (0)-1 and the participation ratio PR() show that at high frequencies, in contrast with similar ones in disordered systems, the phonon eigenstates are delocalized.
کلیدواژه ها:
Fibonacci lattice ، forced oscillator method ، transfer-matrix technique ، phonon density of states ، wave transmission
نویسندگان
s a ketabi
School of Physics, Damghan University of Sciences, Damghan, Iran
n shahtahmasebi
Department of Physics, School of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran