Configuration-enriched magnetoelectronic spectra of AAB-stacked trilayer graphene

Influence of electric fields on absorption spectra of AAB-stacked trilayer graphene

The band structures and optical properties of AAB-stacked trilayer graphenes (AAB-TLG) are calculated by the tight-binding model and gradient approximation. Three pairs of the energy bands exhibit very different energy dispersions at low energy and saddle points at the middle energy. At zero electric field, $3$$^2$ excitation channels exist in both the low and middle frequencies, and cause the very rich joint density of states (JDOS). However, the structures in the JDOS do not appear in the absorption spectra completely. Due to the different contributions from the velocity metric elements, som…

Geometry-diversified Coulomb excitations in trilayer AAB stacking graphene

The lower-symmetry trilayer AAB-stacked graphene exhibits rich electronic properties and thus diverse Coulomb excitations. Three pairs of unusual valence and conduction bands create nine available interband excitations for the undoped case, in which the imaginary (real) part of the polarizability shows 1D square root asymmetric peaks and 2D shoulder structures (pairs of antisymmetric peaks and logarithm type symmetric peaks). Moreover, the low frequency acoustic plasmon, being revealed as a prominent peak in the energy loss spectrum, can survive in a narrow gap system with the large-density-of…

Rich magneto-absorption spectra in AAB-stacked trilayer graphene

The generalized tight-binding model is developed to investigate the feature-rich magneto-optical properties of AAB-stacked trilayer graphene. Three intragroup and six intergroup inter-Landau-level (inter-LL) optical excitations largely enrich the magneto-absorption peaks. In general, the former are much higher than the latter, depending on the phases and amplitudes of LL wavefunctions. The absorption spectra exhibit the single- or twin-peak structures which are determined by the quantum modes, LL energy spectra and Fermion distribution. The splitting LLs, with different localization centers (2…

扭转单层-双层石墨烯中的竞争层间相互作用：从自发电极化到准魔角

Competing interlayer interactions in twisted monolayer-bilayer graphene: From spontaneous electric polarization to quasi-magic angle

本文通过第一性原理与紧束缚模型研究扭转单层-双层石墨烯（aAB）中两个界面层间耦合的竞争，揭示其从大角度自发电极化到小角度类TBG电荷局域化的电子结构演化，并发现1.16度准魔角处出现窄带，表明aAB是研究关联电子现象的有前景平台。

Effects of opposite atoms on electronic structure and optical absorption of two-dimensional hexagonal boron nitride

We perform the first-principles many-body GW and Bethe-Salpeter equation (BSE) calculations on the two-dimensional hexagonal boron nitride (2D-hBN) to explore the effects of opposite atoms on the electronic structure and linear one-photon absorption (OPA). Five AA- and AB-stacked bilayer and eight AAB-stacked trilayer structures are considered. The AAB-stacked trilayer hBN (TL-BN) structures are constructed by mixing the AA- and AB-stacked bilayer hBN (BL-BN). We show that the GW approximation gives rise to different types (i.e., indirect or direct) of fundamental band gaps from the independen…

Stacking-enriched magneto-transport properties of few-layer graphenes

The quantum Hall effects in the sliding bilayer graphene and AAB-stacked trilayer system are investigated by the Kubo formula and the generalized tight-binding model. The various stacking configurations can greatly diversify the magnetic quantization and thus create the rich and unique transport properties. The quantum conductivities are very sensitive to the Fermi energy and magnetic-field strength. The diverse features cover the specific non-integer conductivities, the integer conductivities with the distinct steps, the splitting-created reduction and complexity of quantum conductivity, a va…