“…Even in the absence of the resistive contacts, effective spin injection into a semiconductor can be achieved if the resistance mismatch is reduced by using for spin injectors either a magnetic semiconductor or a highly spin-polarized ferromagnet. 44 While there was early experimental evidence (Alvarado and Renaud, 1992) that employing resistive (tunneling) contacts could lead to an efficient spin injection, 45 a systematic understanding was provided by Rashba (2000) and supported by subsequent experimental and theoretical studies (Fert and Jaffres, 2001;Smith and Silver, 2001;Rashba, 2002b;Johnson, 2003;Johnson and Byers, 2003;Takahashi and Maekawa, 2003). As can 41 Carrier density will also be influenced by the effect of screening, which changes with the dimensionality of the spin injection geometry (Korenblum and Rashba, 2002).…”