arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1911.03466cond-mat.str-el
收藏

同时存在无序和磁场的二维相互作用费米子

Interacting fermions in two dimension in simultaneous presence of disorder and magnetic field

Saptarshi Mandal, Sanjay Gupta

摘要:

本文用平均场近似的无限制Hartree-Fock方法研究了二维正方晶格和蜂窝晶格中无序与电子相互作用竞争引起的Hofstadter蝴蝶的复活。无序和电子关联相互抵消的事实被证实的蜂窝晶格,由于其较少的配位数,这增强了无序的效果,需要更大的电子关联的强度。由于配位数较高,正方形结构中的蝶形结构的复活程度比蜂窝结构中的蝶形结构好。研究了无序度和相互作用对纠缠度的影响,得到了纠缠度的纠缠熵和纠缠谱。研究发现,对于正方形晶格,中等强度磁场下的纠缠熵不符合面积定律,而且这种偏离的程度还取决于无序度和相互作用。然而,这种偏离面积定律是蜂窝晶格所不存在的。此外,正方格子的纠缠谱确实具有原来的Hofstadter蝴蝶的对称性,这种对称性在无序存在时被破坏。这种相互作用也在纠缠谱中打开了一个缺口。对于蜂窝晶格,纠缠谱形成了一个连续的带,没有任何对称性,其特征在无序和相互作用的存在下基本不变。

英文摘要:

We have studied the revival of Hofstadter butterfly due to the competition between disorder and electronic interaction using mean field approximation of unrestricted Hartree Fock method at zero temperature for two dimensional square and honeycomb lattices. Interplay of disorder and electronic correlation to nullify each other is corroborated by the fact that honeycomb lattice needs more strength of electronic correlation owing to its less co-ordination number which enhances the effect of disorder. The extent of revival of the butterfly is better in square than honeycomb lattice due to higher coordination number. The effect of disorder and interaction is also investigated to study entanglement entropy and entanglement spectrum. It has been observed that for the square lattice, area law of entanglement entropy is violated for intermediate strength magnetic and magnitude of such departure from area law depends on disorder and interaction as well. However such departure from area law is absence for honeycomb lattice. Moreover the entanglement spectrum for square lattice does have the symmetry of original Hofstadter butterfly and this symmetry is destroyed in the presence of disorder. The interaction opens up a gap in the entanglement spectrum as well. For the honeycomb lattice, the entanglement spectrum forms a continuous band without any symmetry and its feature is mostly unchanged in the presence of disorder as well as interaction.

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。

↑