[6] J. Chen et al. Optical nano-imaging of gate-tunable graphene plasmons. Nature, 487, 77-81(2012).
[10] G. X. Ni et al. Fundamental limits to graphene plasmonics. Nature, 557, 530-533(2018).
[11] A. B. Khanikaev et al. Photonic topological insulators. Nat. Mater., 12, 233-239(2013).
[18] D. Jin et al. Infrared topological plasmons in graphene. Phys. Rev. Lett., 118, 245301(2017).
[32] L. Xiong et al. Photonic crystal for graphene plasmons. Nat. Commun., 10, 4780(2019).
[40] F. Schindler et al. Higher-order topological insulators. Sci. Adv., 4, eaat0346(2018).
[43] S. Mittal et al. Photonic quadrupole topological phases. Nat. Photonics, 13, 692-696(2019).