Issue |
EPL
Volume 146, Number 3, May 2024
|
|
---|---|---|
Article Number | 36002 | |
Number of page(s) | 7 | |
Section | Condensed matter and materials physics | |
DOI | https://doi.org/10.1209/0295-5075/ad397c | |
Published online | 29 April 2024 |
Topological defects and boundary states in four-dimensional topological insulator
1 Institute of Theoretical Physics, School of Physics and Optoelectronic Engineering, Beijing University of Technology - Beijing 100124, PRC
2 School of Physics, Beihang University - Beijing 100191, PRC
Received: 20 January 2024
Accepted: 2 April 2024
We show the connection between the second Chern number and topological defects, in a (4+1)-dimensional time-reversal invariant Dirac lattice model. It is discovered that two types of topological defects, the five-dimensional (5D) and four-dimensional (4D) point defects arise from the singular points of wave functions together with the geometric meaning of the second Chern number. We demonstrated that the 5D point defects appear at the band crossing positions with a topological transition, leading to a jump of the second Chern number. The 4D point defects exist in an insulating bulk, whose topological charges can give the evaluations of the second Chern number of energy bands. Finally, we discussed the possible structures of the boundary states in the light of the realization way of the 4D model. Our theory provides not only a new perspective to grasp the second Chern number, but also a simple approach to derive its values without calculating any integrals.
© 2024 EPLA
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.