Defect model of the smectic A-nematic phase transition
Defect model of the smectic A-nematic phase transition
复制标题
近晶A-向列相变的缺陷模型
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
W. Helfrich
中科院分区：
文献类型：
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作者：
W. Helfrich
它示出，在三维中打破了有序状态的极性缺陷线的相变可以建模的XY模型，至少如果线的相互作用是唯一的位阻。类比是建立一个晶格模型的xy高温膨胀自旋1/2的装置。将缺陷模型应用于近晶A-向列相转变，将其解释为近晶位错环导致的有序破坏。T < Tc处的临界指向矢波动被解释为这些环的表现。临界行为示出不同于传统的XY模型，因为近晶位错的特殊的弹性相互作用。
It is shown that phase transitions in three dimensions breaking up an ordered state by polar defect lines can be modelled on the xy model, at least if the interaction of the lines is only steric. The analogy is established for a lattice model by means of a xy high-temperature expansion for spin 1/2. The defect model is applied to the smectic A-nematic transition which is interpreted as a breakup of order by smectic dislocation loops. Critical director fluctuations at T < Tc are explained as a manifestation of these loops. Critical behaviour is shown to differ from that of the conventional xy model because of the peculiar elastic interaction of smectic dislocations.