on d - m at / 0 40 34 52 v 1 [ co nd - m at . s of t ] 1 8 M ar 2 00 4 Helical Ribbons as Isometric Textures
نویسنده
چکیده
Deformations that conserve the parallelism and the distances –between layers, in smectic phases; between columns, in columnar phases– are commonplace in liquid crystals. The resulting deformed textures have the same mass density as in the ground state (an expected property in a liquid) and are at the same time isogonic and isometric, which imposes specific geometric features. The corresponding order parameter singularities extend over rather large, macroscopic, distances, e.g., cofocal conics in smectics. This well-known picture is modified when, superimposed to the 1D or 2D periodicities, the structure is helical. Isogony is no longer the rule, but isometry (and mass density) can be preserved. This paper discusses the case of a medium whose structure is made of 1D modulated layers (a lamello-columnar phase), assuming that the modulations rotate helically from one layer to the next. The price to pay is that any isometric texture is necessarily frustrated; it consists of layers folded into a set of parallel helicoids, in the manner of a screw dislocation (of macroscopic ∗author for correspondence; e-mail: [email protected]
منابع مشابه
ar X iv : c on d - m at / 0 20 91 97 v 1 [ co nd - m at . s up r - co n ] 9 S ep 2 00 2 Oxygen Phonon Branches
متن کامل
ar X iv : c on d - m at / 0 40 10 25 v 1 [ co nd - m at . s of t ] 4 J an 2 00 4 Physics of Econophysics
Econophysics is a new area developed recently by the cooperation between economists, mathematicians and physicists. It’s not a tool to predict future prices of stocks and exchange rates. It applies idea, method and models in Statistical Physics and Complexity to analyze data from economical phenomena. In this paper, three examples from three active main topics in Econophysics are presented firs...
متن کاملar X iv : 0 71 2 . 02 55 v 1 [ co nd - m at . s of t ] 3 D ec 2 00 7 Confined nanorods : jamming due to helical buckling
We investigate a longitudinally loaded elastic nanorod inside a cylindrical channel and show within the context of classical elasticity theory that the Euler buckling instability leads to a helical postbuckling form of the rod within the channel. The local pitch of the confined helix changes along the channel and so does the longitudinal force transmitted along the rod, diminishing away from th...
متن کاملRTES-03 Interfaces.indd
[ B ur ns 20 07 ] B u rn s, A & W el lin gs , A C o n cu rr en t a n d R ea l-T im e Pr o gr am m in g in A d a, e d it io n C am b ri d ge U n iv er si ty P re ss 2 00 7 [ M o to ro la 19 96 ] M o to ro la Ti m e Pr o ce ss in g U n it R ef er en ce M an u al 1 99 6 p p . 1 -1 42 [ M o to ro la 20 00 ] M o to ro la M PC 56 5 & M PC 56 6 2 00 0 p p . 1 -1 31 2 [ P ea co ck 19 97 ] Pe ac o ck , ...
متن کاملar X iv : c on d - m at / 0 10 90 27 v 1 [ co nd - m at . s tr - e l ] 3 S ep 2 00 1 The Net Spin Model
We study a set of exactly soluble spin models in one and two dimensions for any spin S. Its ground state, the excitation spectrum, quantum phase transition points, as well as dimensional crossover are determined.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008