scholarly journals Extended states in a one-dimensional generalized dimer model

2002 ◽  
Vol 65 (23) ◽  
Author(s):  
P. Ojeda ◽  
R. Huerta-Quintanilla ◽  
M. Rodríguez-Achach
Keyword(s):  
Dimer Model ◽  
One Dimensional ◽  
Extended States

ANDERSON LOCALIZATION IN THE SEVENTIES AND BEYOND

2010 ◽  
Vol 24 (12n13) ◽  
pp. 1507-1525 ◽  
Author(s):  
David Thouless
Keyword(s):  
Quantum Hall Effect ◽  
Anderson Localization ◽  
Quantum Hall ◽  
Experimental Tests ◽  
Three Dimensions ◽  
Electronic Systems ◽  
Atomic Systems ◽  
One Dimensional ◽  
Extended States ◽  
Energy States

Little attention was paid to Anderson's challenging paper on localization for the first ten years, but from 1968 onwards it generated a lot of interest. Around that time a number of important questions were raised by the community, on matters such as the existence of a sharp distinction between localized and extended states, or between conductors and insulators. For some of these questions the answers are unambiguous. There certainly are energy ranges in which states are exponentially localized, in the presence of a static disordered potential. In a weakly disordered one-dimensional potential, all states are localized. There is clear evidence, in three dimensions, for energy ranges in which states are extended, and ranges in which they are diffusive. Magnetic and spin-dependent interactions play an important part in reducing localization effects. For massive particles like electrons and atoms the lowest energy states are localized, but for massless particles like photons and acoustic phonons the lowest energy states are extended. Uncertainties remain. Scaling theory suggests that in two-dimensional systems all states are weakly localized, and that there is no minimum metallic conductivity. The interplay between disorder and mutual interactions is still an area of uncertainty, which is very important for electronic systems. Optical and dilute atomic systems provide experimental tests which allow interaction to be much less important. The quantum Hall effect provided a system where states on the Fermi surface are localized, but non-dissipative currents flow in response to an electric field.

Extended states in finite one-dimensional, disordered, highly doped, ItransR-polyacetylene chains

1992 ◽  
Vol 45 (6) ◽  
pp. 3107-3110 ◽  
Author(s):  
F. C. Lavarda ◽  
D. S. Galvo ◽  
B. Laks
Keyword(s):  
One Dimensional ◽  
Extended States

Extended states in one-dimensional random potential

1997 ◽  
Vol 103 (1) ◽  
pp. 15-18 ◽  
Author(s):  
G.F Lorusso ◽  
V Capozzi ◽  
J.L Staehli
Keyword(s):  
Random Potential ◽  
One Dimensional ◽  
Extended States

ABSORPTION SPECTRA AND LEVEL SPACING STATISTICS IN A TERNARY ALLOY WITH AN ORNSTEIN–UHLENBECK DISORDER DISTRIBUTION

2014 ◽  
Vol 25 (02) ◽  
pp. 1350091 ◽  
Author(s):  
M. O. SALES ◽  
T. F. ASSUNÇÃO ◽  
S. S. ALBUQUERQUE ◽  
F. A. B. F. DE MOURA
Keyword(s):  
Absorption Spectrum ◽  
Optical Absorption ◽  
Poisson Distribution ◽  
Absorption Spectra ◽  
Optical Absorption Spectrum ◽  
Level Spacing ◽  
Rule Based ◽  
Band Center ◽  
One Dimensional ◽  
Extended States

In this paper, we study the dynamics of a one-electron in a one-dimensional (1d) alloy with a correlated Ornstein–Uhlenbeck (OU) disorder distribution. The model considered here corresponds to an alloy with three types of atoms where the position of each atom is obtained using a stochastic rule based on the OU process. We analyze in detail the effect of this correlated disorder in the optical absorption spectrum and the level spacing statistics near the band center. Our results reveal a new collection of optical absorption peaks. We explain in details the appearance of each peak. Our calculations about the level spacing's distribution reveals a Poisson distribution thus contradicting previous statements about the existence of extended states in ternary electronic models with correlated disorder distribution.

DELOCALIZATION IN ONE-DIMENSIONAL TOPOLOGICALLY DISORDERED SYSTEMS

2009 ◽  
Vol 23 (25) ◽  
pp. 4987-4992 ◽  
Author(s):  
A. BREZINI ◽  
P. FULDE ◽  
M. DAIRI ◽  
A. ZANOUN
Keyword(s):  
Charge Transfer ◽  
Transmission Coefficient ◽  
Electronic Transport ◽  
Disordered Systems ◽  
Short Range ◽  
Localization Length ◽  
Electronic Charge ◽  
One Dimensional ◽  
Extended States ◽  
Electronic Charge Transfer

A Kronig–Penney model with short-range correlated impurities is used to investigate the electronic transport properties of one-dimensional disordered systems simulating both superlattices, protein chains, and polymers. Physical magnitudes characterizing the electronic charge transfer are analytically the transmission coefficient and the localization length. It is shown that a set of delocalized states occurs at particular well-defined energies. The divergence of the localization length is investigated and a critical exponent 1 is found for the barrier case which differs with the results of literature. These results support the idea that the nature of the extended states depend on the typical nature of the correlation in disorder. On this basis, the conductance of disordered superlattices is investigated as well as the relative fluctuations of the transmission coefficient.

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