Arun Bansil1
Northeastern University1
The revolution started by the discovery of topological insulators has turned out to be the proverbial tip of the much larger iceberg of exotic phases harbored by quantum matter. Consideration of electronic states protected by time-reversal, crystalline and particle-hole symmetries is continuing to lead to the prediction of new types of magnetic and non-magnetic topological materials such as the higher-order topological phases and axion insulators, which can support Weyl, Dirac, Majorana and other fermionic excitations unique to condensed matter systems. I will discuss some of our recent theoretical work aimed at predicting topological materials beyond the standard topological insulators and identify cases where robust experimental evidence has been obtained toward their successful materials realization. [1-5] I will also comment on how the special symmetry-protected electronic states in topological materials hold the exciting promise of providing platforms for exploring fundamental science questions, and for the realization of next-generation devices for optoelectronics, spintronics, information processing and other applications.<br/><br/>[1] A. Gao, et al., <i>Nature</i> <i>595</i>, 521 (2021).<br/>[2] B. Wang et al., <i>Physical Review B</i> <i>104</i>, L121108 (2021).<br/>[3] C. Hu et al., <i>Science Advances</i> <i>6</i>, eaba4275 (2020).<br/>[4] I. Belopolski et al., <i>Science</i> <i>365</i>, 1278 (2019).<br/>[5] A. Bansil, H. Lin and T. Das, <i>Reviews of Modern Physics</i> <i>88</i>, 021004 (2016).