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arXiv 1402.6413cond-mat.mes-hallcond-mat.str-el
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菱形三层石墨烯中的巨相互作用诱导能隙和电子相

Giant Interaction-Induced Gap and Electronic Phases in Rhombohedral Trilayer Graphene

Y. Lee, D. Tran, K. Myhro, J. Velasco, N. Gillgren, C. N. Lau, Y. Barlas, J. M. Poumirol, D. Smirnov, F. Guinea

摘要:

由于其独特的电子色散和缺乏费米表面,在未掺杂的二维狄拉克系统,如单层,双层和三层石墨烯中的库仑相互作用可能是边缘或相关的。相关的相互作用可以导致自发对称性破缺,这是造成从高能物理中的质量产生到凝聚态中的相关状态(例如超导性和磁性)的一大类物理现象的原因。在这里,使用传输测量,我们表明,菱形堆叠的三层石墨烯(r-TLG)提供了一个简单的,但新颖的和可调的平台,用于研究具有自发或场诱导的对称性破坏的各种阶段。在这里,我们表明,与紧束缚计算的预测相反,菱形堆叠的三层石墨烯(r-TLG)是一种本征绝缘体,具有巨大的相互作用诱导的间隙Δ~ 42 meV。这种绝缘状态是时间反转对称性被破坏的自发层反铁磁状态,可以通过增加电荷密度n、层间电位、平行磁场或临界温度Tc~ 38 K来抑制。这种有间隙的集体状态可以用于具有低输入功率和高开/关比的开关。

英文摘要:

Due to their unique electron dispersion and lack of a Fermi surface, Coulomb interactions in undoped two-dimensional Dirac systems, such as single, bi- and tri-layer graphene, can be marginal or relevant. Relevant interactions can result in spontaneous symmetry breaking, which is responsible for a large class of physical phenomena ranging from mass generation in high energy physics to correlated states such as superconductivity and magnetism in condensed matter. Here, using transport measurements, we show that rhombohedral-stacked trilayer graphene (r-TLG) offers a simple, yet novel and tunable, platform for study of various phases with spontaneous or field-induced broken symmetries. Here, we show that, contrary to predictions by tight-binding calculations, rhombohedral-stacked trilayer graphene (r-TLG) is an intrinsic insulator, with a giant interaction-induced gap Δ~42meV. This insulating state is a spontaneous layer antiferromagnetic with broken time reversal symmetry, and can be suppressed by increasing charge density n, an interlayer potential, a parallel magnetic field, or a critical temperature Tc~38K. This gapped collective state can be explored for switches with low input power and high on/off ratio.

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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