Details

Autor(en) / Beteiligte

• Wu, DongYu
• Huang, YunPeng
• Sun, Song
• Gao, JiaCheng
• Guo, ZhaoPeng
• Weng, HongMing
• Fang, Zhong
• Jiang, Kun
• Wang, ZhiJun

Titel

Unprotected quadratic band crossing points and quantum anomalous Hall effect in FeB2 monolayer

Ist Teil von

• Science China. Physics, mechanics & astronomy, 2022-05, Vol.65 (5), p.256811, Article 256811

Ort / Verlag

Beijing: Science China Press

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Quadratic band crossing points (QBCPs) and quantum anomalous Hall effect (QAHE) have attracted the attention of both theoretical and experimental researchers in recent years. Based on first-principle calculations, we find that the FeB 2 monolayer is a nonmagnetic semimetal with QBCPs at K. Through symmetry analysis and k · p invariant theory, we find that the QBCP is not protected by rotation symmetry and consists of two Dirac points with the same chirality (Berry phase of 2 π ). Once introducing Coulomb interactions, we find that there is a spontaneous-time-reversal-breaking instability of the spinful QBCPs, which gives rise to a C = 2 QAH insulator with orbital moment ordering.