1211.6825 (K. Hamaya et al.)

Room-temperature detection of spin accumulation in silicon across
Schottky tunnel barriers using a MOSFET structure    [PDF]

K. Hamaya, Y. Ando, K. Masaki, Y. Maeda, Y. Fujita, S. Yamada, K. Sawano, M. Miyao

Using a metal-oxide-semiconductor field effect transistor (MOSFET) structure with a high-quality CoFe/n^+Si contact, we systematically study spin injection and spin accumulation in a nondegenerated Si channel with a doping density of ~ 4.5*10^15cm^-3 at room temperature. By applying the gate voltage (V_G) to the channel, we obtain sufficient bias currents (I_Bias) for creating spin accumulation in the channel and observe clear spin-accumulation signals even at room temperature. Whereas the magnitude of the spin signals is enhanced by increasing I_Bias, it is reduced by increasing V_G interestingly. These features can be understood within the framework of the conventional spin diffusion model. As a result, a room-temperature spin injection technique for the nondegenerated Si channel without using insulating tunnel barriers is established, which indicates a technological progress for Si-based spintronic applications with gate electrodes.

View original: http://arxiv.org/abs/1211.6825