Multifractal analysis of the electronic states in the Fibonacci superlattice under weak electric fields

• Published in: The European physical journal. B, Condensed matter physics Vol. 85; no. 1
• Main Authors: Wołoszyn, M., Spisak, B. J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 2012; EDP Sciences; Springer
• Subjects: Complex Systems; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states; Exact sciences and technology; Fluid- and Aerodynamics; Methods of electronic structure calculations; Physics; Physics and Astronomy; Regular Article; Solid State Physics; Solid State and Materials; Singularity; Fluctuations; Electronic properties; Energy levels; Fibonacci sequences; Energy spectra; Eigenfunctions; Multifractal system; Low field; Level anticrossing; Eigenstates; Electronic structure; Experimental design; Electric field effects; Superlattices; Scaling laws; Electron state; Non linear effect
• ISSN: 1434-6028; 1434-6036
• DOI: 10.1140/epjb/e2011-20745-1

Influence of the weak electric field on the electronic structure of the Fibonacci superlattice is considered. The electric field produces a nonlinear dynamics of the energy spectrum of the aperiodic superlattice. Mechanism of the nonlinearity is explained in terms of energy levels anticrossings. The multifractal formalism is applied to investigate the effect of weak electric field on the statistical properties of electronic eigenfunctions. It is shown that the applied electric field does not remove the multifractal character of the electronic eigenfunctions, and that the singularity spectrum remains non-parabolic, however with a modified shape. Changes of the distances between energy levels of neighbouring eigenstates lead to the changes of the inverse participation ratio of the corresponding eigenfunctions in the weak electric field. It is demonstrated, that the local minima of the inverse participation ratio in the vicinity of the anticrossings correspond to discontinuity of the first derivative of the difference between marginal values of the singularity strength. Analysis of the generalized dimension as a function of the electric field shows that the electric field correlates spatial fluctuations of the neighbouring electronic eigenfunction amplitudes in the vicinity of anticrossings, and the nonlinear character of the scaling exponent confirms multifractality of the corresponding electronic eigenfunctions.