Pressure-Induced Topological Dirac Semimetallic Phase in KCdP

TL;DR

This study predicts that applying negative pressure to KCdP induces a transition from a semiconductor to a topologically protected Dirac semimetal with Dirac cones, highlighting pressure as a tuning parameter for electronic phases.

Contribution

It demonstrates the pressure-driven topological phase transition in KCdP and provides detailed symmetry and electronic structure analysis under negative pressure.

Findings

KCdP transitions from semiconductor to Dirac semimetal under negative pressure.

Dirac cones appear at the Fermi level indicating massless Dirac fermions.

The pressure-induced phase is robust and symmetry-protected.

Abstract

Dirac semimetals (DSMs), characterized by linear dispersion relations in their electronic band structure, have gained prominence due to their unique topological features and potential applications in electronic devices. Through systematic calculation, we explore the electronic structure evolution of KCdP under varying negative pressure conditions. Our findings reveal a compelling transition from a normal semiconductor to a triple point semimetal when spin-orbit coupling (SOC) is not introduced, whereas in the SOC case, it converts into a Dirac semimetallic state in KCdP under negative triaxial pressure. The electronic band structure exhibits distinct Dirac cones at the Fermi level, indicating the presence of massless Dirac fermions. Moreover, the negative pressure-induced Dirac semimetallic phase in this compound is found to be robust and is protected by crystal symmetry. We provide a symmetry analysis of the bandgap, Fermi surface, Fermi velocity, and other relevant electronic properties, offering insights into the pressure-driven phase transition in KCdP. The tunability of this material under external pressure suggests the potential utility in next-generation electronic devices and quantum technologies.