Orientation of electron spins in hybrid ferromagnet–semiconductor nanostructures

摘要: The spin orientation of electrons is studied in ferromagnet (FM)–semiconductor (SC) hybrid structures composed a (Ga,Mn)As ferromagnetic layer, which placed the direct vicinity non-magnetic SC quantum well (QW). It shown that polarization carriers QW achieved by spin-dependent tunnelling into magnetized layer. This leads to dynamical electrons, can be directly observed means time-resolved photoluminescence. We find electron grows time after excitation with an optical pulse and may reach values as large 30%. rate capture exponentially steeply decreasing thickness spacer between layer QW, it persists up Curie temperature From pump–probe Kerr rotation data, we evaluate value only few eV for energy splitting Zeeman sublevels due interaction indicating equilibrium negligible. Schematic presentation semiconductor (QW) under linearly polarized (FM). arrows FM box indicate magnetization . effect detected appearance circular degree photoluminescence pulsed (right). data are 5 nm.