摘要翻译:
我们研究了聚合物的一个晶格模型,其中最近邻单体-单体的相互作用强度根据局域构型是否具有所谓的“类氢”形成而不同。当相互作用强度相同时,随着温度的降低,聚合物发生经典的π-点坍缩转变,进入各向同性液滴相,即坍缩球。另一方面,随着温度的降低,强烈的类氢相互作用会产生各向异性的折叠(类固体)相。我们用长256的蒙特卡罗模拟来绘制参数平面上的相图,并确定相关相变的顺序。我们讨论了与半柔性聚合物和其他聚合物模型的联系。重要的是,我们证明了在一定的能量参数范围内,随着温度的降低会发生两个相变,第二个相变是从球状态到晶体态的转变。根据我们的数据,我们认为这种球到晶体的转变在二维是连续的,这与场论中关于哈密顿游动的论点是一致的,但在三维是一级的。
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英文标题:
《The competition of hydrogen-like and isotropic interactions on polymer
collapse》
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作者:
J Krawczyk, A L Owczarek, T Prellberg
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最新提交年份:
2007
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分类信息:
一级分类:Physics 物理学
二级分类:Soft Condensed Matter 软凝聚态物质
分类描述:Membranes, polymers, liquid crystals, glasses, colloids, granular matter
膜,聚合物,液晶,玻璃,胶体,颗粒物质
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一级分类:Physics 物理学
二级分类:Statistical Mechanics 统计力学
分类描述:Phase transitions, thermodynamics, field theory, non-equilibrium phenomena, renormalization group and scaling, integrable models, turbulence
相变,热力学,场论,非平衡现象,重整化群和标度,可积模型,湍流
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英文摘要:
We investigate a lattice model of polymers where the nearest-neighbour monomer-monomer interaction strengths differ according to whether the local configurations have so-called ``hydrogen-like'' formations or not. If the interaction strengths are all the same then the classical $\theta$-point collapse transition occurs on lowering the temperature, and the polymer enters the isotropic liquid-drop phase known as the collapsed globule. On the other hand, strongly favouring the hydrogen-like interactions give rise to an anisotropic folded (solid-like) phase on lowering the temperature. We use Monte Carlo simulations up to a length of 256 to map out the phase diagram in the plane of parameters and determine the order of the associated phase transitions. We discuss the connections to semi-flexible polymers and other polymer models. Importantly, we demonstrate that for a range of energy parameters two phase transitions occur on lowering the temperature, the second being a transition from the globule state to the crystal state. We argue from our data that this globule-to-crystal transition is continuous in two dimensions in accord with field-theory arguments concerning Hamiltonian walks, but is first order in three dimensions.
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PDF链接:
https://arxiv.org/pdf/706.2162