Higher-order topological insulators(HOTIs)are a newly devel-oped topological phase which hosts higher-codimensional topolog-ical states with lower dimensionality localized at the“boundaries of boundaries”[1,2].There...Higher-order topological insulators(HOTIs)are a newly devel-oped topological phase which hosts higher-codimensional topolog-ical states with lower dimensionality localized at the“boundaries of boundaries”[1,2].There are various methods to induce a higher-order topological phase.A quintessential example is the quadrupole insulator based on the Benalcazar,Bernevig,and Hughes(BBH)model[1],which has vanishing dipole polarization but a quantized quadrupole moment.Due to the extended higher-order bulk-boundary correspondence principle,a tWo-dimensional(2D)quadrupole insulator supports 0D in-gap corner states and 1D gapped edge states.Another canonical approach is to directly generalize the 1D SSH model to higher dimensions.展开更多
基金the support of the National Natural Science Foundation of China(12174339)Fundamental Research Funds for the Central Universities。
文摘Higher-order topological insulators(HOTIs)are a newly devel-oped topological phase which hosts higher-codimensional topolog-ical states with lower dimensionality localized at the“boundaries of boundaries”[1,2].There are various methods to induce a higher-order topological phase.A quintessential example is the quadrupole insulator based on the Benalcazar,Bernevig,and Hughes(BBH)model[1],which has vanishing dipole polarization but a quantized quadrupole moment.Due to the extended higher-order bulk-boundary correspondence principle,a tWo-dimensional(2D)quadrupole insulator supports 0D in-gap corner states and 1D gapped edge states.Another canonical approach is to directly generalize the 1D SSH model to higher dimensions.
