Abstract: A bipolar spin transistor is provided. In one embodiment of the present invention, the bipolar spin transistor includes a first semiconductor region having a first conductivity type, a second semiconductor region having a second conductivity type that is different from the first conductivity type and also having a spin polarization, and a third semiconductor region having a conductivity type that is the same conductivity type of the first semiconductor region. The first semiconductor region and the second semiconductor region are adjacent to each other so as to form a first charge depletion layer therebetween, the first charge depletion layer having a first side facing the first semiconductor region and an opposing second side facing the second semiconductor region.

Abstract: A unipolar spin transistor includes a semiconductor material having a first region, a second region, and a third region. The first region is adjacent to the second region so as to form a first domain between the first region and the second region, and the second region is adjacent to the third region so as to form a second domain between the second region and the third region. A first voltage is provided between the first region and the second region to cause carriers to move across the first domain from the first region to the second region. A second voltage is generated between the second region and the third region to cause the carriers move across the second domain from the second region to the third region. The second voltage has an amplitude different from that of the first voltage. The first region and the third region have a first spin polarization, and the second region has a second spin polarization which may be different from the first spin polarization.

Abstract: The unipolar spin transistor includes a first semiconductor region having a conductivity type and a first spin polarization, and a second semiconductor region having a conductivity type that is the same conductivity type of the first semiconductor region and a second spin polarization that is different from the first spin polarization of the first semiconductor region, and a third semiconductor region having a conductivity type that is the same conductivity type of the first semiconductor region and the first spin polarization. The unipolar spin transistor can also include a magnetic semiconductor wherein the semiconductor material is in a high-resistance state when the second spin polarization of the second region is opposite to the first spin polarization of the first and third regions, and wherein the semiconductor material is in a low-resistance state when the second spin polarization of the second region is aligned to the first spin polarization of the first and third regions.

Abstract: A unipolar spin diode and a unipolar spin transistor. In one embodiment, the unipolar spin diode includes a first semiconductor region having a conductivity type and a spin polarization, and a second semiconductor region having a conductivity type that is the same conductivity type of the first semiconductor and a spin polarization that is different from the spin polarization of the first semiconductor region. The first semiconductor region and the second semiconductor region are adjacent to each other so as to form a spin depletion layer therebetween, the spin depletion layer having a first side and an opposing second side. When a majority carrier in the first semiconductor region moves across the spin depletion layer from the first side of the spin depletion layer to the second side of the spin depletion layer, the majority carrier in the first semiconductor region becomes a minority carrier in the second semiconductor region.