Electric field-tuned spin Seebeck effect in doped SiC nanoribbons

In this work, an electric field-tuned strategy based on dual-atom doping is proposed to achieve precise control of spin-dependent thermoelectric transport in SiC nanoribbons (SiCNRs), using first-principles calculations. The study reveals that dual-atom doping at specific sites of zigzag SiCNRs can regulate spin-dependent transmission coefficients, leading to the emergence of “X"-shaped transmission spectra near the Fermi level. Under this condition, the two spin channels exhibit pronounced opposite signs in their Seebeck coefficients, inducing spin-polarized currents with opposite flow directions. By applying a gate voltage to the central scattering region, the density of states distribution in the doped system can be precisely modulated, thereby enabling a pronounced spin Seebeck effect. The spin Seebeck coefficient reaches a remarkable value of 225 µV/K, significantly surpassing that of conventional doped SiC nanoribbons(\(\sim\)100 µV/K) and edge-doped graphene nanoribbons(\(\sim\)150 µV/K). This dual-atom doping strategy establishes a new paradigm for designing room-temperature spin caloritronic devices with programmable spin current configurations.