| Autor: |
Pieranski P; Université Paris-Saclay, Laboratoire de Physique des Solides, 91405 Orsay, France., Zeghal M; Université Paris-Saclay, Laboratoire de Physique des Solides, 91405 Orsay, France., Godinho MH; i3N/CENIMAT, Department of Materials Science, NOVA School of Science and Technology, NOVA University Lisbon, Campus de Caparica, Caparica 2829 - 516, Portugal., Judeinstein P; Université Paris-Saclay, CEA, CNRS, LLB, 91191 Gif-sur-Yvette, France., Bouffet-Klein R; ENS Paris-Saclay, 4 Avenue des Sciences, 91190 Gif-sur-Yvette, France., Liagre B; ENS Paris-Saclay, 4 Avenue des Sciences, 91190 Gif-sur-Yvette, France., Rouger N; ENS Paris-Saclay, 4 Avenue des Sciences, 91190 Gif-sur-Yvette, France. |
| Abstrakt: |
The concept of topological defects is universal. In condensed matter, it applies to disclinations, dislocations, or vortices that are fingerprints of symmetry breaking during phase transitions. Using as a generic example the tangles of dislocations, we introduce the concept of topological metadefects, i.e., defects made of defects. We show that in cholesterics, dextrogyre and levogyre primary tangles are generated through the D_{2}→C_{2} symmetry breaking from the coplanar dislocation pair called Lehmann cluster submitted to a high enough tensile strain. The primary tangles can be wound up individually into double helices. They can also annihilate in pairs or associate into tangles of higher orders following simple algebraic rules. |
