Probing many-body interactions in the cyclotron resonance of h-BN/bilayer graphene/h-BN
Probing many-body interactions in the cyclotron resonance of h-BN/bilayer graphene/h-BN
复制标题
探讨 h-BN/双层石墨烯/h-BN 回旋共振中的多体相互作用
DOI：
10.1103/physrevb.104.245137
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Tomoki Machida
中科院分区：
文献类型：
--
作者：
Rai Moriya;Sabin Park;Satoru Masubuchi;Kenji Watanabe;Takashi Taniguchi;Tomoki Machida
不同于传统的二维电子气系统，它具有抛物线能带结构，单层到少层石墨烯的非抛物线能带色散违反了科恩定理。因此，石墨烯中的朗道能级（LL）对多体相互作用敏感。根据费米能的位置，这会改变LL间距（）。通过观察称为回旋共振（CR）的LL间光学跃迁，已经在-BN/单层石墨烯/-BN中广泛研究了这种效应。然而，到目前为止，多体相互作用对双层石墨烯（BLG）的CR的影响很少被研究，即使BLG也具有非抛物带色散。在这里，我们调查CR在BN/BLG/BN结构通过磁光热电测量下的红外激光照射。这种方法能够在调谐BLG的同时灵敏地检测回旋共振。当BLG接近电荷中性点（Dirac点，DP）时，CR磁场值发生了明显的变化。我们把这归因于费米速度的变化BLG附近的DP，这是由于多体相互作用。
Unlike a conventional two-dimensional electron gas system, which has parabolic band structure, the nonparabolic band dispersion of mono- to few-layer graphene violates Kohn's theorem. Thus, Landau levels (LLs) in graphene are sensitive to many-body interactions. This modifies the LL spacing, depending on the location of the Fermi energy (). Such effects have been extensively studied in-BN/monolayer graphene/-BN through observation of inter-LL optical transitions known as cyclotron resonances (CRs). However, thus far, the influence of many-body interactions on the CR of bilayer graphene (BLG) has been rarely studied, even though BLG also possesses nonparabolic band dispersion. Here, we investigate CR in the-BN/BLG/-BN structure via magneto-photothermoelectric measurements under infrared laser irradiation. This method enables sensitive detection of cyclotron resonances while tuningof BLG. The CR magnetic field value shifted significantly whenof BLG approached the charge-neutrality point (the Dirac point, DP). We attribute this to a change in the Fermi velocity of BLG near the DP, which occurs as a result of many-body interactions.