Electronic structures and Zeeman splitting in GaAs_1-xBi_x nanowires under axial magnetic fields

Combining the effective-mass theory with valence-band anticrossing model, we investigate the electronic structures and Zeeman splitting characteristics of dilute bismuth GaAs nanowires under axial magnetic fields. Calculated results demonstrate that absorption spectra of GaAs_1-x Bi _x nanowires exhibit a linear relationship of Zeeman splitting energy with magnetic field regardless of the diameter and Bi composition, due to lifting of degeneracy in both electron and hole states. Importantly, we find that enhanced Zeeman splitting energies and effective g factors of GaAs_1-x Bi _x nanowires with larger diameters and lower Bi concentrations can be obtained, which principally arises from splitting energy of the hole states involved in first peaks of σ ⁺ and σ ^- spectra. Further, normalized magnetic circular dichroism spectra corroborate the Zeeman splitting features observed in the absorption spectra. Our research manifests that GaAs_1-x Bi _x nanowires exhibit promising potential for quantum information processing applications because of their large and tunable effective g factors.