20.500.12556/DKUM-66394 Effective topological charge cancelation mechanism 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. topological defects topological charge numerical studies orientational ordering nematic liquid crystals liquid crystalline shells biological membranes nanoparticles Gaussian curvature electrostatic analogy annihilation topology topološki defekti topološki naboj numerične raziskave orientacijski red nematični tekoči kristali tekoče kristalne lupine biološke membrane nanodelci Gaussova ukrivljenost elektrostatična analogija anihilacija topologija true true true Nature Portfolio Angleški jezik Slovenski jezik Znanstveno delo 2017-06-23 10:44:38 2017-06-23 10:45:52 2026-01-08 14:13:23 2019-07-11 15:46:00 2016 0 0 Str. 1-9 št. članka 2717 Letn. 6 2016 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2016-02-02 2016-05-13 2016-06-01 2045-2322 515.1 18727432 22256136 10.1038/srep27117 2045-2322 URN:SI:UM:DK:HNWZJJU0 Scientific_Reports_2016_Mesarec_et_al._Effective_Topological_Charge_Cancelation_Mechanism.pdf Scientific_Reports_2016_Mesarec_et_al._Effective_Topological_Charge_Cancelation_Mechanism.pdf 1 9A7CC422DE7002DDB5876344883269E5 262c5e5ce36996d5a1369f54a3841dfd7175947b9be535e5507b7505ae9d2520 49dd696f-7c0e-11eb-bb7a-00155d0001ca https://dk.um.si/Dokument.php?lang=slv&id=113005 http://www.nature.com/articles/srep27117 1 https://dk.um.si/Dokument.php?lang=slv&id=113004 Fakulteta za naravoslovje in matematiko 0 0 0