A conserved noise restricted solid-on-solid model on both a Sierpinski gasket substrate and a checkerboard fractal substrate is studied. The interface width W grows as t(β) at early time t and becomes saturated at L(α) for t >> L(z), where L is the system size. We obtain β ≈ 0.0788, α ≈ 0.377 for a Sierpinski gasket, and β ≈ 0.100, α ≈ 0.516 for a checkerboard fractal. The dynamic exponent z ≈ 4.79 for a Sierpinski gasket and z ≈ 5.16 for a checkerboard fractal are obtained by the relation z = α/β. They satisfy the scaling relations 4 α + 2 d(f) = z and z = 2 z(rw), where z(rw) is the random-walk exponent of the fractal substrate. A fractional Langevin equation is introduced to describe the model.
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http://dx.doi.org/10.1103/PhysRevE.84.011105 | DOI Listing |
Light Sci Appl
January 2025
Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, and Center for Light-Matter Interaction, Tel Aviv University, Tel Aviv, Israel.
This item from the News and Views (N&V) category aims to provide a summary of theoretical and experimental results recently published in ref. , which demonstrates the creation of corner modes in nonlinear optical waveguides of the higher-order topological insulator (HOTI) type. Actually, these are second-order HOTIs, in which the transverse dimension of the topologically protected edge modes is smaller than the bulk dimension (it is 2, in the case of optical waveguide) by 2, implying zero dimension of the protected modes, which are actually realized as corner or defect ones.
View Article and Find Full Text PDFLight Sci Appl
September 2024
Institute of Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow, 108840, Russia.
Higher-order topological insulators (HOTIs) are unique materials hosting topologically protected states, whose dimensionality is at least by 2 lower than that of the bulk. Topological states in such insulators may be strongly confined in their corners which leads to considerable enhancement of nonlinear processes involving such states. However, all nonlinear HOTIs demonstrated so far were built on periodic bulk lattice materials.
View Article and Find Full Text PDFPhys Rev E
October 2023
Department of Physics, Banaras Hindu University, Varanasi 221 005, India.
We present the (numerically) exact phase diagram of a magnetic polymer on the Sierpińsky gasket embedded in three dimensions using the renormalization group method. We report distinct phases of the magnetic polymer, including paramagnetic swollen, ferromagnetic swollen, paramagnetic collapsed, and ferromagnetic collapsed states. By evaluating critical exponents associated with phase transitions, we located the phase boundaries between different phases.
View Article and Find Full Text PDFNanophotonics
September 2023
Key Laboratory for Physical Electronics and Devices, Ministry of Education, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
We study linear and nonlinear higher-order topological insulators (HOTIs) based on waveguide arrays arranged into Sierpiński gasket and Sierpiński carpet structures, both of which have non-integer effective Hausdorff dimensionality. Such fractal structures possess different discrete rotational symmetries, but both lack transverse periodicity. Their characteristic feature is the existence of multiple internal edges and corners in their optical potential landscape, and the formal absence of an insulating bulk.
View Article and Find Full Text PDFSci Rep
August 2023
Materials Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA.
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