Anisotropic Dirac Fermions in BaMnBi₂ and BaZnBi₂

Area of Science:

• Solid State Physics
• Materials Science
• Condensed Matter Physics

Background:

• Barium manganese bismuthide (BaMnBi2) and barium zinc bismuthide (BaZnBi2) share similar crystal structures.
• Understanding their electronic properties is key to exploring potential applications.

Purpose of the Study:

• To investigate and compare the electronic structures of BaMnBi2 and BaZnBi2.
• To elucidate the factors driving the observed differences in their electronic properties.

Main Methods:

• Angle-resolved photoemission spectroscopy (ARPES) was employed to probe the electronic band structure.
• First-principles calculations were performed to complement experimental findings.

Main Results:

• BaMnBi2 exhibits a highly anisotropic Dirac dispersion with a reduced asymmetry factor compared to related AMnBi2 compounds.
• BaZnBi2 displays a complex Fermi surface topology due to multiple bands crossing the Fermi energy.
• The hybridization between Bi-p and Mn-d/Zn-s states was identified as the primary cause for the electronic structure divergence.

Conclusions:

• The electronic structure of BaMnBi2 and BaZnBi2 are dramatically different despite structural similarities.
• Hybridization effects play a crucial role in determining the electronic properties of these bismuthide compounds.