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Semiconductors

, Volume 39, Issue 9, pp 1048–1052 | Cite as

A spin filter with a quantum point contact in a dilute magnetic semiconductor

  • S. A. Ignatenko
  • V. E. Borisenko
Low-Dimensional Systems

Abstract

Within the context of the suggested quantum-mechanical description of hole transport in the ballistic mode, the feasibility of using a quantum point contact as a spin filter in dilute magnetic semiconductors is analyzed. By studying the example of a dilute ferromagnetic GaxMn1−xAs semiconductor, it is established that even smoothing the potential shape does not allow one to attain a 100% spin polarization of the current; in particular, at a constriction width of 3.5 nm, the polarization is 82%. It is shown that the operation region of such a spin filter lies in the narrow range of constriction widths ∼3.5–4.0 nm, and, at large constriction widths, damped oscillations of the spin polarization of the current occur. The spin-orbit splitting in GaxMn1−xAs is sufficient for real operation of a quantum point contact as a spin filter in this material. An increase in the splitting does not produce a substantial increase in the degree of polarization of the incoming current.

Keywords

Magnetic Material Narrow Range Point Contact Electromagnetism Spin Polarization 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Pleiades Publishing, Inc. 2005

Authors and Affiliations

  • S. A. Ignatenko
    • 1
  • V. E. Borisenko
    • 1
  1. 1.Belarussian State University of Informatics and RadioelectronicsMinskBelarus

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