Scientific Activities
Seminars
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Seminar of Center for Theoretical Physics: | |
| Title | Reflection symmetric second-order topological insulators and superconductors |
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| Speaker | Dr. Luka Trifunovic |
| Affiliation | Freie Universitaet, Berlin |
| Date | Friday, 11-08-2017 |
| Time | 09:30 AM |
| Location | Room 202 (Library), Institute of Physics, 10 Dao Tan, Ba Dinh, Hanoi |
| Abstract | Second-order topological insulators are crystalline insulators with a gapped bulk and gapped crystalline boundaries, but topologically protected gapless states at the intersection of two boundaries. Without further spatial symmetries, five of the ten Altland-Zirnbauer symmetry classes allow for the existence of such second-order topological insulators in two and three dimensions. We show that reflection symmetry can be employed to systematically generate examples of second-order topological insulators and superconductors, although the topologically protected states at corners (in two dimensions) or at crystal edges (in three dimensions) continue to exist if reflection symmetry is broken. A three-dimensional second-order topological insulator with broken time-reversal symmetry shows a Hall conductance quantized in units of e^2/h. |
| Host person | Nguyễn Thị Kim Thanh |