Local chiral symmetry breaking in triatic liquid crystals
Local chiral symmetry breaking in triatic liquid crystals
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DOI：
10.1038/ncomms1803
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发表时间：
2012-01
影响因子：
16.6
通讯作者：
Kun Zhao;R. Bruinsma;T. Mason
中科院分区：
文献类型：
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作者：
Kun Zhao;R. Bruinsma;T. Mason
了解热激发的多粒子系统的行为，由一个单一的粒子类型具有明确的形状和大小，是重要的凝聚态物质，特别是蛋白质结晶。在这里，我们观察并解释了一个令人惊讶的简单系统的硬布朗粒子的局部手征对称性破缺的起源：非手性正三角形局限于两个维度。使用增强的光学视频粒子跟踪显微镜，我们表明，微尺度光刻三角形血小板形成两个不同的triatic液晶相。当粒子面积分数φA ≥ 0.55时，简单的三阶相在空间上是无序的，但具有与六阶液晶不同的分子取向特征。在较高的φA≥0.61时，我们发现第二个triatic相位表现出局部手征对称性破缺;转动熵有利于横向偏移最近邻三角形的位置。通过促成空间无序，局部手征对称性破缺可以限制可以熵结晶的形状的范围。
Understanding the behaviour of thermally excited many-particle systems, composed of a single particle type having a well-defined shape and size, is important in condensed matter, notably protein crystallization. Here we observe and explain the origin of local chiral symmetry breaking in a surprisingly simple system of hard Brownian particles: achiral regular triangles confined to two dimensions. Using enhanced optical video particle-tracking microscopy, we show that microscale lithographic triangular platelets form two different triatic liquid crystal phases. Above a particle area fractionφA≈0.55, the simple triatic phase is spatially disordered, yet has molecular orientational characteristics that distinguish it from a hexatic liquid crystal. At higherφA≥0.61, we find a second triatic phase exhibiting local chiral symmetry breaking; rotational entropy favours laterally offsetting the positions of nearest-neighbouring triangles. By contributing to spatial disordering, local chiral symmetry breaking can limit the range of shapes that can be entropically crystallized.