Volume 142, Number 5, June 2023
|Number of page(s)||7|
|Section||Condensed matter and materials physics|
|Published online||31 May 2023|
Multiple higher-order topological phases with even and odd pairs of zero-energy corner modes in a C3symmetry broken model
1 Institute of Physics - Bhubaneswar, 751005, Odhisa, India
2 Homi Bhabha National Institute - Mumbai, 400 094, Maharashtra, India
3 Department of Physics and Astronomy, Uppsala University - Box 516, 75120 Uppsala, Sweden
Received: 6 March 2023
Accepted: 19 May 2023
Here we study emergent higher-order topological (HOTI) phases in the extended Haldane model without C3 symmetry. For the inversion symmetric case, the QSHI and QAHI phases can embed the HOTI phases while the remaining QASHI phase does not yield any HOTI phases. Remarkably, four-fold degeneracy of zero-energy corner states can be reduced to two-fold under the application (withdrawal) of sub-lattice mass (Zeeman field) term. The sub-lattice mass and Zeeman field terms compete with each other to pin down the two mid-gap states at zero-energy. Interestingly, the bulk polarization can topologically characterize the second-order topological insulator phase with the mid-gap corner modes irrespective of their energies as long as inversion symmetry is preserved. Our study indicates that a hybrid symmetry can in principle protect the second-order topological insulator phases, however, spin-spectrum gap has to be essentially finite there.
© 2023 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.