Birth and annihilation of topological defects on the nematic–isotropic interface during droplet coalescence

ABSTRACT

In our work, we for the first time observed simultaneous birth and subsequent annihilation of two types of defects on nematic–isotropic interface: point boojums and localised equatorial defects. The investigations were made in the two-phase nematic–isotropic region in nematic droplets with conical boundary conditions. We found a new type of localized defects formed from equatorial ring defects in confined geometry of planar optical cells. During coalescence of nematic droplets, we observed formation of four antipodes of boojums and localised equatorial defects, followed by their pairwise annihilation with existing defects. The dynamics of defect annihilation was investigated.

GRAPHICAL ABSTRACT

KEYWORDS:

• Topological defects
• coalescence
• nematics
• conical anchoring
• confined geometry

Disclosure statement

No potential conflict of interest was reported by the author(s).

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Additional information

Funding

The work was supported by the Russian Science Foundation [Grant No. 18-12-00108].