Probing the semiconductor-to-dirac semimetal transition in Na-Sb-Bi alloys with x-ray Compton scattering

2025/06/03 by Pulkkinen, Aki, Kothalawala, Veenavee Nipunika, Suzuki, Kosuke +12
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)

paper · doi:10.48550/arxiv.2506.02833

Abstract

We discuss electron redistribution during the semiconductor-to-Dirac semimetal transition in Na-Sb-Bi alloys using x-ray Compton scattering experiments combined with first-principles electronic structure modeling. A robust signature of the semiconductor-to-Dirac semimetal transition is identified in the spherically averaged Compton profile. We demonstrate how the number of electrons involved in this transition can be estimated to provide a novel descriptor for quantifying the strength of spin-orbit coupling responsible for driving the transition. The associated theoretical deviation of the Born charge of Na in Na₃Bi from the expected ionic charge of +1 is found to be consistent with the corresponding experimental value of about 10%. Our study also shows the sensitivity of the Compton scattering technique toward capturing the spillover of Bi 6p relativistic states onto Na sites.

Citations

• Adiabatic observables and Berry curvatures in insulators and metals
• Boosting the discovery of 3D topological materials: mixing chemistry with physics via a two-step computational screening strategy
• Generalized Gradient Approximation Made Simple
• Relativity and the periodic system of elements

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