  We investigated the resonant tunneling of a two-spin system through the
double quantum dots in Al-N-implanted silicon tunnel FETs (TFETs) by
electrical-transport measurements and Landau-Zener-St\"{u}ckelberg-Majorana
interferometry with and without magnetic fields. Our experimental results
revealed the coexistence of spin-conserving and spin-flip tunneling channels in
the two-spin system in non-zero magnetic fields. Additionally, we obtained the
spin-conserving/spin-flip tunneling rates of the two-spin system through the
double quantum dots in the TFET. These findings will improve our understanding
of the two-spin system in silicon TFET qubits and may facilitate the coherent
control of quantum states through all-electric manipulation.
