Random Tiling and Topological Defects in a Two-Dimensional Molecular Network

Science ◽  
2008 ◽  
Vol 322 (5904) ◽  
pp. 1077-1081 ◽  
Author(s):  
M. O. Blunt ◽  
J. C. Russell ◽  
M. d. C. Gimenez-Lopez ◽  
J. P. Garrahan ◽  
X. Lin ◽  
...  
Keyword(s):  
Topological Defects ◽  
Molecular Network ◽  
Two Dimensional ◽  
Random Tiling

scholarly journals Defects and perturbation

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Enrico M. Brehm
Keyword(s):  
Entanglement Entropy ◽  
Topological Defects ◽  
Field Theories ◽  
Two Dimensional ◽  
Conformal Field Theories ◽  
Minimal Models ◽  
Conformal Field

Abstract We investigate perturbatively tractable deformations of topological defects in two-dimensional conformal field theories. We perturbatively compute the change in the g-factor, the reflectivity, and the entanglement entropy of the conformal defect at the end of these short RG flows. We also give instances of such flows in the diagonal Virasoro and Super-Virasoro Minimal Models.

scholarly journals Properties of twisted topological defects in 2D nematic liquid crystals

Soft Matter ◽  
2021 ◽  
Author(s):  
Daniel Pearce ◽  
Karsten Kruse
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Topological Defects ◽  
Two Dimensional

Topological defects are one of the most conspicuous features of liquid crystals. In two dimensional nematics, they have been shown to behave effectively as particles with both, charge and orientation,...

scholarly journals Tunable two-dimensional polarization grating using a self-organized micropixelated liquid crystal structure

RSC Advances ◽  
2018 ◽  
Vol 8 (72) ◽  
pp. 41472-41479 ◽  
Author(s):  
Reo Amano ◽  
Péter Salamon ◽  
Shunsuke Yokokawa ◽  
Fumiaki Kobayashi ◽  
Yuji Sasaki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Topological Defects ◽  
Self Organization ◽  
Two Dimensional ◽  
Self Organized ◽  
Optical Grating ◽  
Liquid Crystal Structure ◽  
Polarization Grating

A micro-pixelated pattern of a nematic liquid crystal formed by self-organization of topological defects is shown to work as a tunable two-dimensional optical grating.

scholarly journals VORTEX NUCLEATION IN ROTATING BOSE–EINSTEIN CONDENSATE: THE ROLE OF THE BOUNDARY CONDITION FOR THE ORDER PARAMETER

2006 ◽  
Vol 20 (15) ◽  
pp. 2147-2158
Author(s):  
W. V. POGOSOV ◽  
K. MACHIDA
Keyword(s):  
Boundary Condition ◽  
Order Parameter ◽  
Topological Defects ◽  
Einstein Condensate ◽  
Two Dimensional ◽  
Surface Modes ◽  
Bose Einstein Condensate ◽  
Bose Einstein ◽  
Vortex Nucleation

We study the problem of vortex nucleation in rotating two-dimensional Bose–Einstein condensate confined in a harmonic trap. We show that, within the Gross–Pitaevskii theory with the boundary condition of vanishing of the order parameter at infinity, topological defects nucleation occurs via the creation of vortex-antivortex pairs far from the cloud center, where the modulus of the order parameter is small. Then vortices move toward the center of the cloud and antivortices move in the opposite direction but never disappear. We also discuss the role of surface modes.

scholarly journals Nematic topological defects positionally controlled by geometry and external fields

2018 ◽  
Vol 9 ◽  
pp. 109-118 ◽  
Author(s):  
Pavlo Kurioz ◽  
Marko Kralj ◽  
Bryce S Murray ◽  
Charles Rosenblatt ◽  
Samo Kralj
Keyword(s):  
Electric Field ◽  
Topological Charge ◽  
Order Parameter ◽  
Topological Defects ◽  
Two Dimensional ◽  
External Fields ◽  
Nematic Ordering ◽  
Spatial Positioning ◽  
A Charge ◽  
The Impact

Using a Landau–de Gennes approach, we study the impact of confinement topology, geometry and external fields on the spatial positioning of nematic topological defects (TDs). In quasi two-dimensional systems we demonstrate that a confinement-enforced total topological charge of m > 1/2 decays into elementary TDs bearing a charge of m = 1/2. These assemble close to the bounding substrate to enable essentially bulk-like uniform nematic ordering in the central part of a system. This effect is reminiscent of the Faraday cavity phenomenon in electrostatics. We observe that in certain confinement geometries, varying the correlation length size of the order parameter could trigger a global rotation of an assembly of TDs. Finally, we show that an external electric field could be used to drag the boojum fingertip towards the interior of the confinement cell. Assemblies of TDs could be exploited as traps for appropriate nanoparticles, opening several opportunities for the development of functional nanodevices.

MODELS OF FREE COOLING GRANULAR GASES

2001 ◽  
Vol 04 (04) ◽  
pp. 321-331 ◽  
Author(s):  
UMBERTO MARINI BETTOLO MARCONI ◽  
ANDREA BALDASSARRI ◽  
ANDREA PUGLISI
Keyword(s):  
Kinetic Energy ◽  
Lattice Model ◽  
Topological Defects ◽  
Total Momentum ◽  
Granular Gases ◽  
Two Dimensional ◽  
Spatial Structures ◽  
Free Evolution ◽  
Free Cooling

We consider the free evolution of systems of granular particles whose dynamics is characterized by a collision rule which preserves the total momentum, but dissipates the kinetic energy. Starting from an inelastic version of a minimal model proposed by Ulam for a gas of Maxwell molecules, we introduce a new lattice model aimed at investigating the role of dynamical correlations and the onset of spatial order induced by the inelasticity of the interactions. We study, in one- and two-dimensional cases, the velocity distribution, the decay of the energy, the formation of spatial structures and topological defects. Finally, we relate our findings to other models known in other fields.

Two-dimensional rigid molecular network with elastic boundaries for constructing hybrid molecular assemblies

2009 ◽  
Vol 19 (10) ◽  
pp. 1490 ◽  
Author(s):  
Xiaojing Ma ◽  
Yibao Li ◽  
Xiaohui Qiu ◽  
Keqing Zhao ◽  
Yanlian Yang ◽  
...  
Keyword(s):  
Molecular Network ◽  
Two Dimensional ◽  
Molecular Assemblies
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