title: Ring defects in a strongly confined chiral liquid crystal.
abstract: We find numerically that a regular array of isolated ring defects can exist as a stable state in a highly chiral liquid crystal confined in a thin cell imposing fixed planar anchoring at the parallel confining surfaces. This peculiar defect structure can be stable when the cell thickness d is around 3/4 of the helical pitch p. A cell of thickness 3p/4 with parallel surface anchoring is incompatible with helical alignment that favors d=mp/2 (with m being an integer). Formation of ring defects can thus be regarded as a result of frustrations between the helical alignment with a specific pitch and the confining surfaces that prevent it.
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology, Umezono, Tsukuba, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Fukuda
authors.forename: Slobodan
authors.initials: S
authors.lastname: Zumer