Kravchenko, Vladimir Ya.Rashba, Emmanuel2016-03-152003Kravchenko, Vladimir Ya., and Emmanuel I. Rashba. 2003. “Spin Injection into a Ballistic Semiconductor Microstructure.” Physical Review B 67 (12) (March 31). doi:10.1103/physrevb.67.121310.1098-0121http://nrs.harvard.edu/urn-3:HUL.InstRepos:25884368A theory of spin injection across a ballistic ferromagnet-semiconductor-ferromagnet junction is developed for the Boltzmann regime. Spin injection coefficient γ is suppressed by the Sharvin resistance of the semiconductor r∗N=(h/e2)(π2/SN), where SN is the Fermi-surface cross-section. It competes with the diffusion resistances of the ferromagnets rF, and γ∼rF/r∗N≪1 in the absence of contact barriers. Efficient spin injection can be ensured by contact barriers. Explicit formulae for the junction resistance and the spin-valve effect are presented.en-USMesoscale and Nanoscale PhysicsJournal Article2016-01-29Vladimir Ya. Kravchenko and Emmanuel I. Rashba2016-03-1510.1103/physrevb.67.121310