, 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


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.


Magnetic Material Narrow Range Point Contact Electromagnetism Spin Polarization 
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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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