Supplementary Materials for Bipolar Altermagnetic Semiconductor in Ti2Br2O Monolayer

The supplementary materials include: computational methods, derivation of Hamiltonian and eigenvalues, model parameters and the corresponding electronic band structures, electron localization function, experimental feasibility, magnetic states and stability, PDOS and orbital-resolved band structure, local magnetic moment and super-exchange interaction, carrier mobilities, band structures under different uniaxial strains,
the calculation of spin-resolved conductivity, and direction-dependent current density of Ti2Br2O ML. Moreover, the relevant Tables S1-S8, Figs. S1-S20, and equations SE1-S45 are also included.