Patent ID: 7309887

Claim:
A spintronics device spin polarizer, comprising: a nonmagnetic semiconductor; a ferromagnetic layer formed above the semiconductor; and a thin degenerate semiconductor layer formed between the ferromagnetic layer and the semiconductor, wherein the thin degenerate semiconductor layer is more highly doped than the semiconductor; wherein the concentration of shallow donors N d + in the thin degenerate semiconductor layer satisfies the condition 4πN d + α B 3 /3>1, where a B is the Borh radius of the shallow donor; and wherein the thickness, l, of the thin degenerate semiconductor layer satisfies the condition: 6l 0 ≦2l D ≦l<<L s + wherein: l 0 represents a tunneling length for a Schottky barrier near a junction between the ferromagnetic layer and the thin degenerate semiconductor layer given by the equation l 0 =( 2 /8π 2 m*Δ) 1/2 ; where represents the Planks constant; m* represents the effective mass of electrons in the thin degenerate semiconductor layer; Δ represents the height of the Schotty barrier; l D represents a thickness of the Schottky barrier given by l D =(2εε 0 Δ/q 2 N d + ) 1/2 ; and L S + represents a length of electron spin in the thin degenerate semiconductor layer given by the equation L S + =√{square root over (D + τ s + )} where D + and τ S + are diffusion coefficient and time of spin coherence of electrons in the thin degenerate semiconductor layer, respectively.