Perturbation-driven spin susceptibility in bilayer <i>P6mmm</i> borophene

Abstract This study addresses the tunability of Pauli spin paramagnetic susceptibility (PSPS) in bilayer P6mmm borophene through internal and external perturbations. We investigate the interplay of excitonic effects from electron-hole interactions within and across layers, external electric fields applied via dual-gate electrodes, and chemical doping with donor and acceptor atoms, using a tight-binding framework. Our results demonstrate that these perturbations typically suppress PSPS by reducing the electronic density of states. However, in the strong-coupling regime, synergistic effects of electric fields and excitonic interactions amplify PSPS and shift its peak to higher temperatures. These findings offer critical insights for tailoring the spin susceptibility of bilayer borophene across a wide temperature range. Tuning PSPS can help stabilize exotic phases like topological insulators or Weyl semimetals, which are foundational for next-generation electronics.