Knots as a Topological Order Parameter for Semiflexible Polymers
Knots as a Topological Order Parameter for Semiflexible Polymers
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DOI：
10.1103/physrevlett.116.128301
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发表时间：
2016-03-21
影响因子：
8.6
通讯作者：
Janke, Wolfhard
中科院分区：
文献类型：
--
作者：
Marenz, Martin;Janke, Wolfhard
结合多正则蒙特卡罗算法和副本交换方法，研究了弯曲刚度对珠棒状均聚物模型构象相的影响，给出了半柔性聚合物从柔性到刚性的全过程的相图。虽然这是一个简单的模型，但我们观察到了丰富多样的构象相，这让人想起观察到的合成聚合物或生物聚合物的构象。根据弯曲刚度的不同，模型会显示不同的伪相，如弯曲、发夹或环形。特别是，我们发现了热力学上稳定的纽结和不寻常的转变，这些纽结相有明显的相共存，但平均总能量几乎不变，因此几乎没有潜热。
Using a combination of the multicanonical Monte Carlo algorithm and the replica-exchange method, we investigate the influence of bending stiffness on the conformational phases of a bead-stick homopolymer model and present the pseudophase diagram for the complete range of semiflexible polymers, from flexible to stiff. Although it is a simple model, we observe a rich variety of conformational phases, reminiscent of conformations observed for synthetic polymers or biopolymers. Depending on the bending stiffness, the model exhibits different pseudophases like bent, hairpin, or toroidal. In particular, we find thermodynamically stable knots and unusual transitions into these knotted phases with a clear phase coexistence, but almost constant mean total energy, and hence almost no latent heat.