物理与电信工程学院学术报告
报告题目：Floquet Higher Order Topological Insulators: Anomalous Dynamical Polarization and Dynamical Singularity
报告人：黄飚 （德国马普所博士后）
会议时间：2020/4/17 19:30-22:00
邀请人：朱诗亮教授
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https://meeting.tencent.com/s/5EdIV6bfa737
会议 ID：767 443 837

报告摘要：The theoretical and experimental discovery of topological insulators of higher multipole nature, dubbed “higher order topological insulators” (HOTI), has triggered heated discussions in recent studies. Until recently, all researches have been limited to static systems due to the lack of higher order topological invariants constructed for a genuine dynamical system. Here, we report a Floquet-driven model showing the anomalous corner states and a construction of dynamical topological invariant built upon evolution operators $ U(t) $. We show that the bulk static nested quadrupoles, constructed by eigenstates of the static Floquet operator $ U_F = U(T) $, vanish identically, while corner states emerge in all energy gaps with quantized charges  due to the dynamical topology. The signature of such an anomalous Floquet phase in cold atom experiments is also discussed via corner particle dynamics and a band tomography. Our work paves the way to a systematic study of HOTI to regimes far away from equilibrium.

相关论文：
1. Haiping Hu, BH, W. Vincent Liu, Erhai Zhao, “Dynamical singularities of Floquet higher-order topological insulators”, Phys. Rev. Lett. 124,052007 (2020) 
2. BH and W. Vincent Liu, “Higher order Floquet topological insulators with anomalous corner modes”, ArXiv:1811.00555 
3. Hong-Chen Jiang, Chang-Yan Wang, BH, Yuan-Ming Lu,  ArXiv: 1809.08247 
4. BH and W. Vincent Liu, Phys. Rev. B100,144202 (2019) 
5. BH  wt al.,  Phys. Rev. B97,195141 (2018).
6. BH et al.,Phys. Rev. Lett. 120,110603 (2018) 
7 BH et al., Phys. Rev. B95,054404 (2017)
8.Tin-Lun Ho and BH, , Phys. Rev. Lett. 115, 155304 (2015)