arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0706.0044cond-mat.stat-mech
收藏

七角晶格中XY模型的相变

Phase Transition of XY Model in Heptagonal Lattice

Seung Ki Baek, Petter Minnhagen, Beom Jun Kim

摘要:

我们数值研究了负曲率七边形晶格中XY模型的相变性质,并与其他相互作用结构如平面二维正方形晶格和小世界网络进行了比较。虽然七边形晶格与小世界网络结构一样具有很短的特征路径长度,但通过计算Binder累积量发现,七边形晶格具有零温相变,而七边形晶格具有平均场性质的有限温相变.通过计算低温近似下的涡旋密度和关联函数,我们发现,没有相变是由于强自旋波型涨落引起的,这一点与通常的二维XY模型有关.

英文摘要:

We numerically investigate the nature of the phase transition of the XY model in the heptagonal lattice with the negative curvature, in comparison to other interaction structures such as a flat two-dimensional (2D) square lattice and a small-world network. Although the heptagonal lattice has a very short characteristic path length like the small-world network structure, it is revealed via calculation of the Binder's cumulant that the former exhibits a zero-temperature phase transition while the latter has the finite-temperature transition of the mean-field nature. Through the computation of the vortex density as well as the correlation function in the low-temperature approximation, we show that the absence of the phase transition originates from the strong spinwave-type fluctuation, which is discussed in relation to the usual 2D XY model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑