Effective Topological Charge Cancelation Mechanism
نویسندگان
چکیده
Topological defects (TDs) appear almost unavoidably in continuous symmetry breaking phase transitions. The topological origin makes their key features independent of systems' microscopic details; therefore TDs display many universalities. Because of their strong impact on numerous material properties and their significant role in several technological applications it is of strong interest to find simple and robust mechanisms controlling the positioning and local number of TDs. We present a numerical study of TDs within effectively two dimensional closed soft films exhibiting in-plane orientational ordering. Popular examples of such class of systems are liquid crystalline shells and various biological membranes. We introduce the Effective Topological Charge Cancellation mechanism controlling localised positional assembling tendency of TDs and the formation of pairs {defect, antidefect} on curved surfaces and/or presence of relevant "impurities" (e.g. nanoparticles). For this purpose, we define an effective topological charge Δmeff consisting of real, virtual and smeared curvature topological charges within a surface patch Δς identified by the typical spatially averaged local Gaussian curvature K. We demonstrate a strong tendency enforcing Δmeff → 0 on surfaces composed of Δς exhibiting significantly different values of spatially averaged K. For Δmeff ≠ 0 we estimate a critical depinning threshold to form pairs {defect, antidefect} using the electrostatic analogy.
منابع مشابه
Use of a Two-Channel Moiré Wavefront Sensor for Measuring Topological Charge Sign of the Vortex Beam and Investigation of Its Change Due to an Odd Number of Reflections
One of the solutions of the Helmholtz equation is the vortex beams. In the recent decades, production and applications of these types of beams have found serious attentions. Determination of the vortex beam topological charge and its sign are very important issues. Odd number of reflections of the vortex beam changes its vorticity. In this paper, we have used a q-plate to generate a vortex beam...
متن کاملHawking radiation of black p-branes via gauge and gravitational anomalies
We investigate the Hawking radiation of black p-branes in superstring theories through the method of anomaly cancelation proposed by Robinson andWilczec et al. The metrics of black p-branes are spherically symmetric, but not the Schwarzschild type generally. We find that in order to make the method of Robinson and Wilczec et al. effective for the calculation of Hawking fluxes for general non-Sc...
متن کاملA topological mechanism of discretization for the electric charge
We present a topological mechanism of discretization, which gives for the fundamental electric charge the value q0 = √ h̄c = 5.29×10−19 C, about 3.3 times the electron charge. Its basis is the following recently proved property of the standard linear classical Maxwell equations: they can be obtained by change of variables from an underlying topological theory, using two complex scalar fields φ a...
متن کاملHadron ?
We present a picture of confinement based on representation of quarks as pointlike topological defects. The topological charge carried by quarks and confined in hadrons is explicitly constructed in terms of Yang-Mills variables. In 2+1 dimensions we are able to construct a local complex scalar field V (x), in terms of which the topological charge is Q = − i 4π d 2 xǫ ij ∂ i (V * ∂ i V − c.c.). ...
متن کاملTopological Analysis of Theoretical Charge Density of Alkali Metal Cations (LC, Na+, le)ICrown Ether (18e6) Complexes
The DO1(18c6)fi (MwLi. Na. K and I 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.The B3LYP/6-3I+G(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). By the aid of fundamental physical theor...
متن کامل