Spin-polarized resonant tunneling in double-barrier structures

Transparency of electron tunneling through double barriers of strained hetero-structures like InAs/GaSb/InAs/GaSb/InAs and Si/Si0.75Ge0.25/Si/Si0.75Ge0.25/Si has been calculated as a function of electron energy using the proposed model which includes the combined effects of Dresselhaus and in-plane Rashba spin-orbit interactions. Enhanced spin-polarized resonant tunneling in the double-barrier heterostructures due to Dresselhaus and Rashba spin-orbit coupling induced splitting of the resonant level is observed. Strong suppression of spin-down transmission in SiGe heterostructures is observed. This effect could be employed in the fabrication of spin filters.