Quantum gates using spin states of triple quantum dot

We present a new model of quantum gates using electron spins of triplely coupled quantum dots. By using the energy selectivity of both photon-assisted tunneling and spin rotation of electrons, logic gates are realized by static and rotational magnetic field and resonant optical pulses. We used what we call a “tunneling qubit”, which realized the switching of interaction between quantum bits. Possibility of the extension to many-qubit-system is also discussed.