Large spin Seebeck effect in flexible V2Se2O layered altermagnet

Recently, two-dimensional (2D) altermagnetic materials have emerged as promising candidates for next-generation energy-efficient spintronic and spin-caloritronic devices. This potential arises from their unique symmetry-breaking characteristics and their intrinsic spin-split electronic band structures. Here, we employ first-principles calculations based on the Boltzmann transport formalism to investigate the spin-dependent thermoelectric transport properties of the layered V 2 Se 2 O system. The V 2 Se 2 O is a direct band gap semiconductor (0.68 eV for monolayer, 0.72 eV for bilayer), exhibiting substantial intrinsic spin splitting (1.14 eV for monolayer, 1.04 eV for bilayer). Furthermore, high Néel temperatures of 600 K (monolayer) and 595 K (bilayer) indicate strong magnetic stability. Notably, we found substantial effective spin Seebeck coefficient values of 1.04 mV/K (monolayer) and 1.16 mV/K (bilayer). These values exceed those reported for other bulk and conventional two-dimensional magnetic and non-magnetic systems, suggesting promising spin caloritronic performance in the material. Additionally, low in-plane rigidity and moderate lateral strain resistance suggest enhanced mechanical flexibility. This combination of strong spin-heat coupling and mechanical flexibility in V 2 Se 2 O suggests its potential for applications in flexible spintronic and spin-caloritronic devices.