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New Topology & Tunable Superconductivity in a-Bi4I4

Nov 16, 2021
Given that ๐œท-Bi4I4 is the first weak topological insulator (TI) (identified by us, but not shown here), that ๐œถ-Bi4I4 is a prototype higher-order TI (highlighted here), and that there is a room-temperature transition between the two structural phases (also identified by us, but not shown here), we have established a new (quasi-1D) TI paradigm that unifies the first and second order topological insulators. The topological nature of ๐œถ-Bi4I4 was not predicted by topological quantum chemistry (or symmetry indicators) that has exhaustively analyzed all the available materials in the materials database. Thus, our results imply the possible existence of many topological materials beyond the scope of our current knowledge and accelerate the discovery of a new generation of functional materials in the topological age.

Authors

R.J. Birgeneau (Berkeley), C. N. Lau (Ohio St.),B. Lv, F. Zhang (UT-Dallas), M. Yi (Rice)

Additional Materials

U.S. National Science Foundation and NSF DMREF, Materials for Our Future

This material is based upon work supported by the U.S. National Science Foundation Award No. 2015237. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the U.S. National Science Foundation. This site is maintained collaboratively by principal investigators with NSF DMREF awards, independent of the NSF.