Theory of quantum corrections to conductivity of granular metal films is developed for the realistic case of large randomly distributed tunnel conductances. Quantum fluctuations of intergrain voltages (at energies E much below the bare charging energy scale E(C)) suppress the mean conductance g (E) much more strongly than its standard deviation sigma(E). At sufficiently low energies E(*) any distribution becomes broad, with sigma(E(*)) approximately g (E(*)), leading to strong local fluctuations of the tunneling density of states. The percolative nature of the metal-insulator transition is established by a combination of analytic and numerical analysis of the matrix renormalization group equations.
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Polymers (Basel)
December 2024
Department of Physics, University of Milano-Bicocca, Piazza della Scienza 3, 20126 Milano, Italy.
We start presenting an overview on recent applications of linear polymers and networks in condensed matter physics, chemistry and biology by briefly discussing selected papers (published within 2022-2024) in some detail. They are organized into three main subsections: polymers in physics (further subdivided into simulations of coarse-grained models and structural properties of materials), chemistry (quantum mechanical calculations, environmental issues and rheological properties of viscoelastic composites) and biology (macromolecules, proteins and biomedical applications). The core of the work is devoted to a review of theoretical aspects of linear polymers, with emphasis on self-avoiding walk (SAW) chains, in regular lattices and in both deterministic and random fractal structures.
View Article and Find Full Text PDFNat Commun
November 2024
Department of Materials Science and Engineering, Graduate School of Engineering, Tohoku University, Sendai, Japan.
Like the crystallization of water to ice, magnetic transition occurs at a critical temperature after the slowing down of dynamically fluctuating short-range correlated spins. Here, we report a unique type of magnetic transition characterized by a linear increase in the volume fraction of unconventional static short-range-ordered spin clusters, which triggered a transition into a long-range order at a threshold fraction perfectly matching the bond percolation theory in a new quantum antiferromagnet of pseudo-trigonal Cu(OH)Cl. Static short-range order appeared in its Kagome lattice plane below ca.
View Article and Find Full Text PDFACS Omega
October 2024
Division of Organic Electronics, Department of Chemistry, Central University of Tamil Nadu, Thiruvarur 610 005, India.
ACS Appl Mater Interfaces
October 2024
Centre for Advanced Optoelectronics, School of Physics and Electronic Information, Gannan Normal University, Ganzhou 341000, China.
Phys Rev E
September 2024
School of Mathematical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
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