Interaction-induced metallic state in graphene on hexagonal boron nitride
Interaction-induced metallic state in graphene on hexagonal boron nitride
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六方氮化硼石墨烯中相互作用诱导的金属态
DOI：
10.1103/physrevb.94.195103
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发表时间：
2016-11
影响因子：
3.7
通讯作者：
Yu-Zhong（张宇钟）
中科院分区：
文献类型：
--
作者：
Xu;Jin-Rong;Song;Ze-Yi;Yuan;Chen-Guang;Zhang;Yu-Zhong（张宇钟）
众所周知，库仑相互作用可以增强相互作用粒子的有效质量，因此往往有利于相应填充时的局部状态。在这里，我们将证明，与这种共识相反，在由石墨烯和六方氮化硼（h-BN）组成的范德华异质结构中，现场库仑排斥首先会破坏局域态。这是因为现场库仑斥力往往会抑制 h-BN 基质引起的相邻碳之间的不对称性。我们通过求解在相干势近似下处理的现场库仑斥力的紧束缚模型来证实这一令人惊讶的现象，其中跳跃参数是根据基于石墨烯/h-BN异质结构的密度泛函理论计算得出的。我们的结果表明，在考虑现场库仑斥力的实际值以及不同的层间距离后，可以理解在石墨烯/h-BN异质结构中实验观察到的无间隙和有间隙状态。最后，我们提出了增强带隙态的方法，这对于石墨烯在下一代电子产品中的潜在应用至关重要。此外，我们认为多体效应抑制的带隙应该发生在其他范德华异质结构中。
The Coulomb interaction is widely known to enhance the effective mass of interacting particles and therefore tends to favor a localized state at commensurate filling. Here, we will show that, in contrast to this consensus, in a van der Waals heterostructure consisting of graphene and hexagon boron nitride (h-BN), the onsite Coulomb repulsion will at first destroy the localized state. This is due to the fact that the onsite Coulomb repulsion tends to suppress the asymmetry between neighboring carbons induced by h-BN substrate. We corroborate this surprising phenomenon by solving a tight-binding model with onsite Coulomb repulsion treated within coherent potential approximation, where hopping parameters are derived from density functional theory calculations based on the graphene/h-BN heterostructure. Our results indicate that both gapless and gapped states observed experimentally in graphene/h-BN heterostructures can be understood after a realistic value of the onsite Coulomb repulsion as well as different interlayer distances are taken into account. Finally, we propose ways to enhance the gapped state which is essential for potential application of graphene to next-generation electronics. Furthermore, we argue that band gap suppressed by many-body effect should happen in other van der Waals heterostructures.
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DOI：
10.1088/0953-8984/26/47/475602
发表时间：
2014-09
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
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通讯作者：
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影响因子：
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影响因子：
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通讯作者：
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DOI：
10.1098/rspa.1963.0204
发表时间：
1963-01-01
影响因子：
--
作者：
HUBBARD, J
通讯作者：
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影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J