Double helical defects in smectic A and smectic A* phases

Abstract

Double helical (DH and DH*) domains, defects of the smectic A (SmA) phase, have for the first time been studied in the smectic A* (SmA*) phase, composed of chiral molecules. Both left-and right-handed DH*s are found in SmA*s, but not in equal numbers. The majority of the DH*s in the two left-handed cholesterics studied are lefthanded, whereas in the SmA phase of non-chiral molecules the DHs are left-and right-handed in equal numbers. DHs and DH*s, which are topologically screw dislocations of giant Burgers vectors, appear to be significantly distorted with respect to a geometrically ideal model. It has been shown that imperfections in the DH*s and DHs are covered by a combination of three types of elementary distortions. The relation between the pitch in DH* and DH and temperature is discussed.

The 2010 Luckhurst–Samulski Prize

“…The next paper was by Nastishin and co-workers entitled Double helical defects in smectic A and smectic A * phases [14] which presents a remarkable, rigorous and beautiful investigation of topological defects in liquid crystal phases but written in such a way as to be accessible to a wider audience.…”