Spin Control by Electric Field
We have experimentally confirmed that the spin-orbit interaction in a semiconductor 2DEG channel can be controlled by a gate voltage. This is the first step towards the creation of functional spin devices such as a spin field effect transistor, a spin filter, and a spin interference device.

Semiconductor/Ferromagnet hybrid structure
Ferromagnetic metal (FM) /semiconductor (SM) hybrid structures can be used to inject a spin polarized current into the SM. Spin-injection into semiconductor is a key to realize a spin-FET, in which the coherent spin state is tuned by an electric field.

Kondo Effect and RKKY Interaction in Quantum Dot Devices
Local spins in quantum dots interact with conduction electrons and the Kondo effect is induced. Indirect exchange interaciton between local spins, i.e., the RKKY interaction, induces high spin in QDs.

Quantum Dot Superlattices
A lattice of coherently coupled quantum dots in a periodic pattern has an energy band diagram which can be engineered by fabrication. Kagome dot-lattice has a dispersionless flat band and exhibits ferromagnetism.