论文标题
偏见交替扭转多层石墨烯的电子结构
Electronic structure of biased alternating-twist multilayer graphene
论文作者
论文摘要
从理论上讲，我们研究了垂直电场下交替的扭转多层石墨烯（ATMG）的能量和光吸收光谱。我们通过一阶退化状态扰动理论在分析中分析了ATMG的低能有效哈密顿量，直至在层间偏置的情况下，并提出了为任意数量的层构建有效的Hamiltonian的一般规则。我们的分析结果同意扭曲角度的数值计算$θ\ gtrsim 2.2^{\ circ} $具有出色的准确性，该计算大于典型的魔术角范围。我们还计算ATMG的光导率并确定其特性光谱，这是通过层间偏置调节的。当在ATMG连续层之间应用层间电位差时，在两个MoiréBrillouinZone Corners $ \ bar {k} $和$ \ bar {k}'$上获得不同的费米速度的狄拉克锥，通常在单层素谱烯和单层在能源上分配的速度较小的FERMI速度，并且在能源上均具有序列的序列功能。
We theoretically study the energy and optical absorption spectra of alternating twist multilayer graphene (ATMG) under a perpendicular electric field. We obtain analytically the low-energy effective Hamiltonian of ATMG up to pentalayer in the presence of the interlayer bias by means of first-order degenerate-state perturbation theory, and present general rules for constructing the effective Hamiltonian for an arbitrary number of layers. Our analytical results agree to an excellent degree of accuracy with the numerical calculations for twist angles $θ\gtrsim 2.2^{\circ}$ that are larger than the typical range of magic angles. We also calculate the optical conductivity of ATMG and determine its characteristic optical spectrum, which is tunable by the interlayer bias. When the interlayer potential difference is applied between consecutive layers of ATMG, the Dirac cones at the two moiré Brillouin zone corners $\bar{K}$ and $\bar{K}'$ acquire different Fermi velocities, generally smaller than that of monolayer graphene, and the cones split proportionally in energy resulting in a step-like feature in the optical conductivity.
