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arXiv 1409.6237cond-mat.str-elcond-mat.quant-gas
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由RKKY相互作用实现拓扑莫特绝缘体

Realizing Topological Mott Insulators from the RKKY Interaction

Tianhan Liu, Benoît Douçot, Karyn Le Hur

摘要:

我们在蜂窝晶格上的费米子-费米子混合物中设计拓扑绝缘相,而不求助于人工规范场或自旋轨道耦合,只考虑局部相互作用。从本质上讲,在有限的掺杂区域中积分出快分量(其特征在于较大的跳跃幅度)后,我们获得了半填充时慢费米子之间的有效相互作用,这在狄拉克锥的两个谷中获得了具有相反宇称的Half质量,从而触发了量子反常霍尔效应。我们仔细地分析了感应Semenoff型质量(在真实空间中产生电荷密度波序)与Haldron质量(量子异常霍尔相位)之间的竞争,作为快费米子化学势的函数。如果第二种物质涉及自旋1/2的粒子,这种相互作用可能会引起量子自旋霍尔相。这种费米子-费米子混合物可以在光晶格或石墨烯异质结构中实现。

英文摘要:

We engineer topological insulating phases in a fermion-fermion mixture on the honeycomb lattice, without resorting to artificial gauge fields or spin-orbit couplings and considering only local interactions. Essentially, upon integrating out the fast component (characterized by a larger hopping amplitude) in a finite region of dopings, we obtain an effective interaction between the slow fermions at half-filling, which acquires a Haldane mass with opposite parity in the two valleys of the Dirac cones, thus triggering a quantum anomalous Hall effect. We carefully analyze the competition between the induced Semenoff-type mass (producing charge density wave orders in real space) versus the Haldane mass (quantum anomalous Hall phase), as a function of the chemical potential of the fast fermions. If the second species involves spin-1/2 particles, this interaction may induce a quantum spin Hall phase. Such fermion-fermion mixtures can be realized in optical lattices or in graphene heterostructures.

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。

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