Electronic Structure Modifications of Lanthanum Pnictides under High Pressure and Implications for Superconductivity

Lanthanum pnictides (LaY, where Y = N, P, As, Sb, Bi) are a compelling class of materials whose electronic and topological properties are highly tunable under high pressure. Using first-principles density functional theory (DFT), this study explores the evolution of electronic structure, density of states (DOS), orbital hybridization, Fermi surface topology, and topological characteristics of LaY compounds under pressures up to 50 GPa. Results reveal that increasing pressure induces band broadening and metallization across the series, with lighter pnictides transitioning from semiconducting to metallic behavior and heavier counterparts exhibiting enhanced semimetallicity. Notably, LaSb and LaBi display pressure-driven spin–orbit coupling (SOC)-induced band inversions, confirming their nontrivial topological character through parity eigenvalue analysis at timereversal invariant momentum (TRIM) points. Calculated DOS at the Fermi level shows a pressure-dependent increase, correlating with a rise in estimated superconducting transition temperatures (Ts). Fermi surface complexity also increases under pressure, supporting favorable conditions for superconductivity. These findings highlight the critical role of pressure in manipulating the quantum states of LaY compounds and suggest promising pathways for engineering topological superconductors for next-generation electronic and quantum devices.