Semiconductor structures, low-dimensional systems, quantum phenomena

Spin filtration of unpolarized electrons by impurity centers in semiconductors

E. G. Bobin, V. L. Berdinskii

Orenburg State University

Abstract: It is shown that unpolarized paramagnetic centers can implement the spin filtration of unpolarized conduction electrons in semiconductors. This ability of paramagnetic centers is caused by the difference in the spin evolution of the states of electron-paramagnetic-center pairs and by the spin selectivity of electron capture exclusively from singlet pairs. The electron spin polarization should be opposite to the paramagneticcenter polarization. To implement spin filtration, an external magnetic field is necessary. The polarization can attain the largest values ($\sim$10%) if the probability of spin-selective electron capture from singlet pairs exceeds the pair-decay rate by a factor of 5–7.

Received: 07.02.2011
Accepted: 11.04.2011

 English version: Semiconductors, 2011, 45:11, 1441–1446

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