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Spin transport between two semiconductors of widely different band gaps is time resolved by two-color pump-probe optical spectroscopy. Electron spin coherence is created in a GaAs substrate and subsequently appears in an adjacent ZnSe epilayer at temperatures ranging from 5 to 300 K. The data show that spin information can be protected by transport to(More)
Recent studies of n-type semiconductors have demonstrated spin-coherent transport over macroscopic distances, with spin-coherence times exceeding 100 ns; such materials are therefore potentially useful building blocks for spin-polarized electronics ('spintronics'). Spin injection into a semiconductor (a necessary step for spin electronics) has proved(More)
Magnetic circular dichroism is used to investigate the evolution of ferromagnetism in the p-type magnetic semiconductor ͑Ga 12x Mn x ͒As. Local Mn moments and holes produce two spectroscopically distinct contributions, whose properties reveal an antiferromagnetic Mn-hole alignment in the ferromagnetic state. These components are present in both metallic and(More)
We examine how a ferromagnetic layer affects the coherent electron spin dynamics in a neighboring gallium arsenide semiconductor. Ultrafast optical pump-probe measurements reveal that the spin dynamics are unexpectedly dominated by hyperpolarized nuclear spins that align along the ferromagnet's magnetization. We find evidence that photoexcited carriers(More)
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