Ribeiro Mauricio S, Nobre Fernando D, Curado Evaldo M F
Centro Brasileiro de Pesquisas Físicas and National Institute of Science and Technology for Complex Systems Rua Xavier Sigaud 150 22290-180 Rio de Janeiro, RJ, Brazil.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Aug;90(2):026101. doi: 10.1103/PhysRevE.90.026101. Epub 2014 Aug 28.
A system of interacting vortices is considered as an appropriate model for describing properties of type-II superconductors, and it has been shown lately to be deeply associated with nonextensive statistical mechanics. Herein we comment on a recent investigation of this model [M. Girotto, A. P. dos Santos, and Y. Levin, Phys. Rev. E 88, 032118 (2013)], which tried to contradict this assertion, based on a mean-field type of solution, compared with numerical-simulation data that correspond typically to a regime characterized by low concentrations of particles, as well as very high temperatures. It is shown that the physical situations analyzed differ significantly from those of a real superconducting phase. The analytical solution obtained from such a mean-field approximation shows a discrepancy with respect to the results of molecular-dynamics numerical simulations, which increases as the temperature is lowered towards the superconducting phase, as expected. We demonstrate that these results, when interpreted properly by means of an analytical solution within the framework of nonextensive statistical mechanics, present a remarkable agreement between molecular-dynamics simulations and theoretical results, for all temperatures, specially for those temperatures associated with the existence of type-II superconductivity.
相互作用的涡旋系统被视为描述II型超导体特性的合适模型，并且最近已表明它与非广延统计力学密切相关。在此，我们对该模型的一项近期研究进行评论[M. 吉罗托、A. P. 多斯桑托斯和Y. 莱文，《物理评论E》88, 032118 (2013)]，该研究基于一种平均场类型的解，与通常对应于低粒子浓度和非常高温度 regime的数值模拟数据相比，试图反驳这一断言。结果表明，所分析的物理情况与真实超导相的情况有显著差异。从这种平均场近似得到的解析解与分子动力学数值模拟结果存在差异，正如预期的那样，随着温度朝着超导相降低，这种差异会增大。我们证明，当在非广延统计力学框架内通过解析解正确解释这些结果时，对于所有温度，特别是与II型超导存在相关的那些温度，分子动力学模拟和理论结果之间呈现出显著的一致性。
