论文标题
三层石墨烯/HBNMoiré超级突变性中电子相关的光谱特征
Spectroscopy Signatures of Electron Correlations in a Trilayer Graphene/hBN Moiré Superlattice
论文作者
论文摘要
ABC堆叠的三角烯石墨烯/HBNMoiré超级晶格（TLG/HBN）已成为相关电子物理学的操场。我们报告了使用傅立叶转化的红外光电流光谱法对双门控TLG/HBN进行光谱测量。我们观察到Moiré迷你带之间的强烈光学跃迁，随着带门的打开，随着带隙的打开，它连续变窄，表明单个粒子带宽的降低。在价值平面频带的半填充时，在约18 meV处出现了一个宽的吸收峰，表明在新兴的mott间隙上直接的光学激发。在第一个传导带的四分之一和半填充时，在其他两个相关的绝缘状态下观察到了相似的光电流光谱。我们的发现提供了Hubbard模型的关键参数，以理解TLG/HBN中电子相关性。
ABC-stacked trilayer graphene/hBN moiré superlattice (TLG/hBN) has emerged as a playground for correlated electron physics. We report spectroscopy measurements of dual-gated TLG/hBN using Fourier transformed infrared photocurrent spectroscopy. We observed a strong optical transition between moiré mini-bands that narrows continuously as a bandgap is opened by gating, indicating a reduction of the single particle bandwidth. At half-filling of the valence flat band, a broad absorption peak emerges at ~18 meV, indicating direct optical excitation across an emerging Mott gap. Similar photocurrent spectra are observed in two other correlated insulating states at quarter- and half-filling of the first conduction band. Our findings provide key parameters of the Hubbard model for the understanding of electron correlation in TLG/hBN.
