One-dimensional quasiperiodic systems with power-law hopping, 1/r^{a}, differ from both the standard Aubry-André (AA) model and from power-law systems with uncorrelated disorder. Whereas in the AA model all single-particle states undergo a transition from ergodic to localized at a critical quasidisorder strength, short-range power-law hops with a>1 can result in mobility edges. We find that there is no localization for long-range hops with a≤1, in contrast to the case of uncorrelated disorder. Systems with long-range hops rather present ergodic-to-multifractal edges and a phase transition from ergodic to multifractal (extended but nonergodic) states. Both mobility and ergodic-to-multifractal edges may be clearly revealed in experiments on expansion dynamics.
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http://dx.doi.org/10.1103/PhysRevLett.123.025301 | DOI Listing |
Materials (Basel)
December 2024
Physics Faculty, West University of Timisoara, Bd. V. Parvan, No. 4, 300223 Timisoara, Romania.
Three elastomer samples were prepared using GS530SP01K1 silicone rubber (ProChima). The samples included pure silicone rubber (SR), a silicone rubber-graphene composite (SR-GR), and a silicone rubber-magnetite composite (SR-FeO). The magnetite was synthesized via chemical precipitation but was not washed to remove residual ions.
View Article and Find Full Text PDFPhys Rev E
October 2024
Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1211, USA.
A central unsolved problem in percolation theory over the past five decades has been whether there is a direct relationship between the critical exponents that characterize the power-law behavior of the transport properties near the percolation threshold, particularly the effective electrical conductivity σ_{e}, and the exponents that describe the morphology of percolation clusters. The problem is also relevant to the relation between the static exponents of percolation clusters and the critical dynamics of spin waves in dilute ferromagnets, the elasticity of gels and composite solids, hopping conductivity in semiconductors, solute transport in porous media, and many others. We propose an approach to address the problem by showing that the contributions to σ_{e} can be decomposed into several groups representing the structure of percolation networks, including their mass and tortuosity, as well as constrictivity that describes the fluctuations in the driving potential gradient along the transport paths.
View Article and Find Full Text PDFJ Phys Condens Matter
November 2024
Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
Ferrite thin films are explored due to their promising properties, which are essential in various advanced electronic devices. However, depositing a film with pure phase and uniform microstructure is challenging. The NiCoFeOferrite thin films are deposited using pulsed laser deposition technique to explore the effect of thickness on structural properties, growth evolution, temperature-dependent dielectric behavior, and conduction mechanisms.
View Article and Find Full Text PDFRSC Adv
September 2024
Laboratoire de recherche Matériaux Avancés et Nanotechnologies (LRMAN), Institut Supérieur des Sciences Appliquées et de Technologie de Kasserine, Université de Kairouan BP 471 Kasserine 1200 Tunisia
This article reveals the crucial structural, magnetic, and electrical properties of LaSrNaMnTiO (LSNMTO) manganite, highlighting the significance of this material in the field of materials science. Gain a deeper understanding of the promising properties of LSNMTO and its potential for technological advancement by delving into this informative article. The X-ray diffraction data of the LSNMTO indicate that this ceramic solid solution crystallizes in the 3̄ rhombohedral structure.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2024
Electrical Engineering, Ingram School of Engineering, Texas State University, San Marcos, Texas 78666, United States.
Thermally induced dielectric and conductivity properties of an Sn-doped β-GaO (-201) single crystal were investigated by frequency-domain impedance spectroscopy in the frequency window from 100 Hz to 1 MHz with temperatures between 293 and 873 K. The (-201) plane-orientated single crystalline nature and the presence of an Sn dopant in β-GaO were confirmed by X-ray diffraction (XRD) and X-ray photoelectron (XPS) spectroscopy. Two different trends of impedance spectra have been discussed by the modulation of relaxation times and semiconductor to metallic transition after ∼723 K due to activation of a significant number of Sn dopants and their movements with temperature.
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