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Journal of Superconductivity

, Volume 18, Issue 2, pp 145–149 | Cite as

Spin Properties of Electrons in Low-Dimensional SiGe Structures

  • W. Jantsch
  • H. Malissa
  • Z. Wilamowski
  • H. Lichtenberger
  • G. Chen
  • F. Schäffler
  • G. Bauer
Article

Abstract

Using ESR, we investigate g-factor and spin coherence time τ of electrons confined in 2D Si1−xGe x {channels} (x < 0.1) by barriers with x > 0.2 and in SiGe quantum dots grown on prepatterned Si substrates. The quantum wells exhibit 2D-anisotropy of both g and τ which can be explained in terms of the Bychkov–Rashba field. The latter increases with increasing Ge content in the well indicating that the increasing spin-orbit coupling is more important than interface properties. The narrow ESR permits selective spin manipulation already for x > 0.02. Large, regular arrays of Ge quantum dots (about 109) were grown on prepatterned substrates. Strain in the Si capping layer lowers the conduction band relative to that of Ge causing confinement. The g-shift observed implies the possibility of g-tuning by confinement. The line width shows substantial inhomogeneous broadening whereas the longitudinal spin lifetime is hardly changed with respect to 2D structures.

Keywords

g-factor tuning quantum dots spin relaxation silicon 

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Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  • W. Jantsch
    • 1
  • H. Malissa
    • 1
  • Z. Wilamowski
    • 2
  • H. Lichtenberger
    • 1
  • G. Chen
    • 1
  • F. Schäffler
    • 1
  • G. Bauer
    • 1
  1. 1.Institut für Halbleiter- und FestkörperphysikJohannes Kepler UniversitaetLinzAustria
  2. 2.Institut PhysicsPolish Academy of SciencesWarsawPoland

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