The inelastic spin Seebeck effects in a controllable Aharonov–Bohm interferometer based on a molecular quantum dot

• We develop a new numerical method to implement the calculation for inelastic Fano-resonance thermoelectric transport.
• When the electrodes' direct coupling is open, the magnetic flux can modulate the line-shape of thermoelectric functions regularly.
• The pure spin current generation can be achieved by the temperature gradient and the electrodes' direct coupling.
• When the electrodes' coupling is closed, the spin-dependent thermoelectric efficiency will be raised greatly and the heating to the phonon bath can improve it effectively.

Using non-equilibrium Green's functions' technology combined with small polaron transformation, we theoretically study the inelastic spin Seebeck effects in a controllable Aharonov–Bohm interferometer based on a degenerate molecular quantum dot level. The numerical results show that when the direct coupling between electrodes is switched on, the spin-dependent thermoelectric efficiency will be suppressed, but the magnetic flux can modulate the thermoelectric line-shapes regularly and the pure spin current generation can be achieved by the temperature gradient. When the direct coupling between electrodes is closed, the spin-dependent thermoelectric efficiency will be raised greatly and the heating resulting from the electron–phonon coupling can improve it effectively.