arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1201.1689cond-mat.str-el
收藏

轨道选择性相变的一般机制

A General Mechanism for Orbital Selective Phase Transitions

Yu-Zhong Zhang, Hunpyo Lee, Hai-Qing Lin, Chang-Qin Wu, Harald O. Jeschke, Roser Valenti

摘要:

基于平均场方法对双轨道哈伯德模型的分析,我们提出了一种轨道选择性相变(OSPT)机制,在该机制中局域电子和巡游电子可以共存.我们发现,这OSPT存在于和接近半填充,即使在没有晶体场分裂或当带宽,轨道简并和磁状态是相等的两个轨道提供的轨道有不同的频带色散。在许多材料中,这些条件一般都应满足。我们发现,这种OSPT是不敏感的洪德规则耦合的强度和重掺杂有利于共线反铁磁态的OSPT。我们讨论我们的结果与铁pnictides。

英文摘要:

Based on the analysis of a two-orbital Hubbard model within a mean-field approach, we propose a mechanism for an orbital selective phase transition (OSPT) where coexistence of localized and itinerant electrons can be realized. We show that this OSPT exists both at and near half filling even in the absence of crystal field splittings or when bandwidths, orbital degeneracies and magnetic states are equal for both orbitals provided the orbitals have different band dispersions. Such conditions should be generally satisfied in many materials. We find that this OSPT is not sensitive to the strength of Hund's rule coupling and that heavy doping favors the collinear antiferromagnetic state over the OSPT. We discuss our results in relation to the iron pnictides.

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。

↑