Non-Hermitian Hopf-Link Exceptional Line Semimetals
Abstract
We study a new class of non-Hermitian topological phases in three dimension, where the topological robust band degeneracies are Hopf-link exceptional lines. As a concrete example, we investigate the non-Hermitian band structure of nodal line semimetals under non-Hermitian perturbations, where the Fermi surfaces can transit from 1d nodal lines to 2d twisting surfaces with Hopf-link boundaries. The topological invariants of these linked exceptional line phases are also proposed. Due to non-Hermitian skin effect, We also find a huge difference between the band structure of periodic and open boundary conditions. After complexification of the momentum in the Bloch Hamiltonian, we find the correct bulk-boundary correspondence in non-Hermitian system. The possible experimental realizations are also discussed.
Ministry of Science and Technology of China 973 program (No. 2015CB921300, No. 2017YFA0303100), National Science Foundation of China (Grant No. NSFC- 1190020, 11534014, 11334012), and the Strategic Prior- ity Research Program of CAS (Grant No.XDB07000000).- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARL03009Z