Hall conductance of a non-Hermitian Weyl semimetal

Autor: Soumi Dey, Ayan Banerjee, Debashree Chowdhury, Awadhesh Narayan
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: New Journal of Physics, Vol 26, Iss 2, p 023057 (2024)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/ad2b0e
Popis: In recent years, non-Hermitian (NH) topological semimetals have garnered significant attention due to their unconventional properties. In this work, we explore one of the transport properties, namely the Hall conductance of a three-dimensional dissipative Weyl semi-metal formed as a result of the stacking of two-dimensional Chern insulators. We find that unlike Hermitian systems where the Hall conductance is quantized, in presence of non-Hermiticity, the quantized Hall conductance starts to deviate from its usual nature. We show that the non-quantized nature of the Hall conductance in such NH topological systems is intimately connected to the presence of exceptional points. We find that in the case of open boundary conditions, the transition from a topologically trivial regime to a non-trivial topological regime takes place at a different value of the momentum than that of the periodic boundary spectra. This discrepancy is solved by considering the non-Bloch case and the generalized Brillouin zone (GBZ). Finally, we present the Hall conductance evaluated over the GBZ and connect it to the separation between the Weyl nodes, within the non-Bloch theory.
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