Nucleation of Topologically Equivalent Phases after Annihilation of Topological Defects


  • Milan Svetec Pomurje Science and Innovation Centre, Lendavska ulica 28, Rakičan, 9000 Murska Sobota; University of Maribor, Faculty of natural sciences and mathematics, Koroška c. 160, 2000 Maribor



The annihilation of radial and hyperbolic point defects within an infinite cylinder of radius R in nematic liquid crystals using Brownian molecular dynamics simulations is studied. Unlike some other studies, where they focus on individual phases of annihilation, this paper considers the entire course of annihilation, both before and after the collision of the two defects. After the collision, merging of defects, and building of a ring disclination structure, the system can experience a structural transition into another topologically equivalent nematic structure, triggered by the nucleation of the ring disclination structure. In the article, the condition under which the transition to the topologically equivalent final structure of the molecular arrangement occurs is quantitatively determined. In addition, a comparison of the temporal evolution of the final stable structure is discussed, where, based on a simple dissipation relation, we obtain an equation that agrees well with the simulation results.


Topological defects, Annihilation of defects, nucleation, liquid crystals, Brownian molecular dynamics


Bradač, Zlatko, Samo Kralj, Milan Svetec, and Slobodan Žumer. "Annihilation of nematic point defects: postcollision scenarios." Physical Review E 67, no. 5 (2003): 050702.

Bradač, Zlatko, Samo Kralj, and Slobodan Žumer. "Molecular dynamics study of nematic structures confined to a cylindrical cavity." Physical Review E 58, no. 6 (1998): 7447.

Cheng, Yuan, Xinbao Zhao, Wanshun Xia, Quanzhao Yue, Yuefeng Gu, and Ze Zhang. "The overview of the formation mechanisms of topologically close-packed phases in Ni-based single crystal superalloys." Materials & Design (2023): 112582.

De Gennes, Pierre-Gilles, and Jacques Prost. The physics of liquid crystals. No. 83. Oxford university press, 1993.

De Luca, Gino, and Alejandro D. Rey. "Ringlike cores of cylindrically confined nematic point defects." The Journal of chemical physics 126, no. 9 (2007).

Fumeron, Sébastien, Bertrand Berche, and Fernando Moraes. "Geometric theory of topological defects: methodological developments and new trends." Liquid Crystals Reviews 9, no. 2 (2021): 85-110.

Fumeron, Sébastien, and Bertrand Berche. "Introduction to topological defects: from liquid crystals to particle physics." The European Physical Journal Special Topics 232, no. 11 (2023): 1813-1833.

Gao, Ningbo, S-G. Je, M-Y. Im, Jun Woo Choi, Masheng Yang, Qin-ci Li, T. Y. Wang et al. "Creation and annihilation of topological meron pairs in in-plane magnetized films." Nature communications 10, no. 1 (2019): 5603.

Lebwohl, Paul A., and Gordon Lasher. "Nematic-liquid-crystal order-a Monte Carlo calculation." Physical Review A 6, no. 1 (1972): 426.

Lifshitz E. M, Pitaevskii L. P. "Physical Kinetics" Vol. 10 of Landau and Lifshitz course of theoretical physics, Oxford: Pergamon Press, 1981.

Pargellis, Andrew, Neil Turok, and Bernard Yurke. "Monopole-antimonopole annihilation in a nematic liquid crystal." Physical review letters 67, no. 12 (1991): 1570.

Skačej, Gregor, V. M. Pergamenshchik, A. L. Alexe-Ionescu, Giovanni Barbero, and Slobodan Žumer. "Subsurface deformations in nematic liquid crystals: The hexagonal lattice approach." Physical Review E 56, no. 1 (1997): 571.

Skogvoll, Vidar, Jonas Rønning, Marco Salvalaglio, and Luiza Angheluta. "A unified field theory of topological defects and non-linear local excitations." npj Computational Materials 9, no. 1 (2023): 122.

Svetec, M., S. Kralj, Z. Bradač, and S. Žumer. "Annihilation of nematic point defects: pre-collision and post-collision evolution." The European Physical Journal E 20, no. 1 (2006): 71-79.

Virga, E.G., 2018. Variational theories for liquid crystals. Chapman and Hall/CRC.





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