First-principles study of the effective Hamiltonian for Dirac fermions with spin-orbit coupling in two-dimensional molecular conductor α-(BETS)2I3
First-principles study of the effective Hamiltonian for Dirac fermions with spin-orbit coupling in two-dimensional molecular conductor α-(BETS)2I3
复制标题
二维分子导体α-(BETS)2I3中自旋轨道耦合狄拉克费米子有效哈密顿量的第一性原理研究
DOI：
10.1140/epjb/s10051-020-00038-y
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Suzumura Yoshikazu
中科院分区：
文献类型：
--
作者：
Tsumuraya Takao;Suzumura Yoshikazu
采用第一性原理密度泛函理论（DFT）方法研究了准二维分子导体-（BETS）[=-（BEDT-TSeF）]中的狄拉克电子在30 K低温下的性质。我们提供了一个紧束缚模型，从最大本地化的Wannier函数，其中相关的转移积分的数量是相对较大的，由于离域字符Seporbitals分子间转移能量评估。自旋-轨道耦合产生一个奇异的绝缘状态，间接带隙约为2毫电子伏。我们用一个靠近费米能级的狄拉克锥来分析能谱，从而建立了一个含有位势的有效哈密顿量，它再现了由DFT能带结构得到的能谱。图形摘要
AbstractWe employed first-principles density-functional theory (DFT) calculations to characterize Dirac electrons in quasi-two-dimensional molecular conductor-(BETS)[=-(BEDT–TSeF)] at a low temperature of 30 K. We provide a tight-binding model with intermolecular transfer energies evaluated from maximally localized Wannier functions, where the number of relevant transfer integrals is relatively large due to the delocalized character of Seporbitals. The spin–orbit coupling gives rise to an exotic insulating state with an indirect band gap of about 2 meV. We analyzed the energy spectrum with a Dirac cone close to the Fermi level to develop an effective Hamiltonian with site potentials, which reproduces the spectrum obtained by the DFT band structure.Graphic abstract