Quantum Monte Carlo studies of edge magnetism in chiral graphene nanoribbons
Quantum Monte Carlo studies of edge magnetism in chiral graphene nanoribbons
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DOI：
10.1103/physrevb.87.155441
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发表时间：
2013-03
影响因子：
3.7
通讯作者：
Michael Golor;T. C. Lang;S. Wessel
中科院分区：
文献类型：
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作者：
Michael Golor;T. C. Lang;S. Wessel
我们研究手性石墨烯纳米带使用投影量子Monte Carlo模拟在本地Hubbard模型描述和研究电子-电子相互作用的电子和磁性的影响在带的边缘。静态和动态特性进行了分析，不同的宽度和边缘手性的纳米带，并比较自洽的Hartee-Fock平均场近似。我们的研究结果表明，对于足够宽的手征带，自旋相关性表现出非常长的相关长度，即使是锯齿形的部分，以及间隔定期扶手椅区域。在不同的带状宽度和手性的磁相关特性增强与紧束缚极限的这种带的能隙。我们确定了特定的签名，在当地的光谱函数，这直接关系到增强的电子相关性沿着石墨烯纳米带的状态和低能量模式的局部密度。局域态密度中的这些特征可以通过石墨烯纳米带上的扫描隧道光谱来访问。
We investigate chiral graphene nanoribbons using projective quantum Monte Carlo simulations within the local Hubbard-model description and study the effects of electron-electron interactions on the electronic and magnetic properties at the ribbons' edges. Static and dynamical properties are analyzed for nanoribbons of varying width and edge chirality and compared to a self-consistent Hartee-Fock mean-field approximation. Our results show that for chiral ribbons of sufficient width, the spin correlations exhibit exceedingly long correlation lengths, even between zigzag segments that are well separated by periodic armchair regions. Characteristic enhancements in the magnetic correlations for distinct ribbon widths and chiralities are associated with energy gaps in the tight-binding limit of such ribbons. We identify specific signatures in the local density of states and low-energy modes in the local spectral function which directly relate to enhanced electronic correlations along graphene nanoribbons. These signatures in the local density of states might be accessed by scanning tunneling spectroscopy on graphene nanoribbons.