Formation scenarios for nonlinear patterns in electroconvection under controlling goldstone modes in magnetic field

Jong Hoon Huh, Yoshiki Hidaka, Shoichi Kai

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

We report novel scenarios for the transitions from a stationary periodic state to spatio-temporal chaos (STC) for electroconvection in homeotropically aligned nematics, in which a constant magnetic field H is applied perpendicularly to an electric field. Above a characteristic frequency fL (in the normal roll regime), when increasing the applied electric field, stationary periodic roll patterns become unstable, and evolve to STC at a certain electric field. For f > fL we find the second stationary periodic roll pattern (i.e., abnormal rolls) at higher electric fields for H > H*, where H* is a characteristic magnetic intensity. At much higher electric field the reentrant stationary periodic rolls evolve to STC again. Reentrant stationary rolls are not observed for H < H*. Below fL (in the oblique roll regime), on the other hand, with increasing the electric field, stationary periodic rolls also become unstable toward STC. In the oblique roll regime, however, we find no reentrant stationary rolls below and above H*. The abnormal roll instability responsible for the reentrant rolls corresponds to a homogeneous azimuthal rotation of the director and plays important role for the novel scenarios. Based on systematic studies, we have determined phase diagrams in the H - ε plane, where ε is a normalized electric voltage.

Original languageEnglish
Pages (from-to)1567-1577
Number of pages11
JournalJournal of the Physical Society of Japan
Volume68
Issue number5
DOIs
Publication statusPublished - 1999

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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