Metal-insulator transition in a disordered nanotube
Autor: | Sohrab Behnia, J. Ziaei |
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Rok vydání: | 2017 |
Předmět: |
Physics
Anderson localization Condensed matter physics General Mathematics Applied Mathematics General Physics and Astronomy Statistical and Nonlinear Physics 02 engineering and technology 021001 nanoscience & nanotechnology Critical value 01 natural sciences Square lattice Delocalized electron Tight binding 0103 physical sciences Metal–insulator transition 010306 general physics 0210 nano-technology Singularity spectrum Wave function |
Zdroj: | Chaos, Solitons & Fractals. 99:101-108 |
ISSN: | 0960-0779 |
DOI: | 10.1016/j.chaos.2017.03.062 |
Popis: | According to the Anderson localization theory, the wavefunctions of a sufficiently strong disordered system are localized. We show that shifting hopping energy between nearest neighbors would induce an anomalous localization-delocalization transition in a disordered square lattice nanotube modelled by tight-binding. For this purpose, the consecutive level spacing statistics and the singularity spectrum analyses were performed. The quantum analysis of singularity spectrum reveals distinctive multifractality structures of the wavefunctions associated with localized and delocalized phases. We find that while in finite-size limit the system has a sudden metal-insulator transition, in large-scale limit the system experiences a rapid but continuous crossover. Interestingly, we report a critical value of hopping energy for which the system behavior is fairly close to metallic phase and especially independent of the system size. Passing this critical value, a great difference in the electronic transport properties of the system occurs. It follows that in the large-scale size, the system tends to follow semi-metallic behavior, while in finite size behaves more like to an insulator. The localization-delocalization transition is also reflected in the electrical current. In accordance with the indicators studied, we find that in delocalized regime there is a spreading electrical current throughout the whole system with an azimuthal symmetric characteristic. |
Databáze: | OpenAIRE |
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