Nearly semi-elliptic relation between the minimal conductivity and Hall conductivity in unpaired Dirac fermions

Fuente: arXiv
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Hauptverfasser: Fu, Bo, Bai, Kai-Zhi, Bi, Shi-Hao, Shen, Shun-Qing
Format: Preprint
Veröffentlicht: 2025
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author Fu, Bo
Bai, Kai-Zhi
Bi, Shi-Hao
Shen, Shun-Qing
author_facet Fu, Bo
Bai, Kai-Zhi
Bi, Shi-Hao
Shen, Shun-Qing
contents Electric conductivities may reveal the topological and magnetic properties of band structures in solids, especially for two-dimensional unpaired Dirac fermions. In this work, we evaluate the longitudinal and Hall conductivity for unpaired Dirac fermions in the framework of the self-consistent Born approximation and find a nearly semi-elliptic relation between the minimal conductivity and Hall conductivities in the Dirac fermions. Near the charge neutrality point, disorder may drive a metal-insulator transition, and enhance the longitudinal conductivity. For the massless case, the minimal conductivity $σ_{xx}^*$ coexists with the half-quantized Hall conductivity $e^2/2h$, forming an indicator for the parity anomalous semimetal. The relation signals a disorder-induced metallic phase that bridges two topologically distinct insulating phases, and agrees with the recent experimental observation in magnetic topological insulators.
format Preprint
id arxiv_https___arxiv_org_abs_2511_10972
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Nearly semi-elliptic relation between the minimal conductivity and Hall conductivity in unpaired Dirac fermions
Fu, Bo
Bai, Kai-Zhi
Bi, Shi-Hao
Shen, Shun-Qing
Mesoscale and Nanoscale Physics
Electric conductivities may reveal the topological and magnetic properties of band structures in solids, especially for two-dimensional unpaired Dirac fermions. In this work, we evaluate the longitudinal and Hall conductivity for unpaired Dirac fermions in the framework of the self-consistent Born approximation and find a nearly semi-elliptic relation between the minimal conductivity and Hall conductivities in the Dirac fermions. Near the charge neutrality point, disorder may drive a metal-insulator transition, and enhance the longitudinal conductivity. For the massless case, the minimal conductivity $σ_{xx}^*$ coexists with the half-quantized Hall conductivity $e^2/2h$, forming an indicator for the parity anomalous semimetal. The relation signals a disorder-induced metallic phase that bridges two topologically distinct insulating phases, and agrees with the recent experimental observation in magnetic topological insulators.
title Nearly semi-elliptic relation between the minimal conductivity and Hall conductivity in unpaired Dirac fermions
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2511.10972