AIP Advances (Oct 2014)

Impact of artificial lateral quantum confinement on exciton-spin relaxation in a two-dimensional GaAs electronic system

  • Takayuki Kiba,
  • Toru Tanaka,
  • Yosuke Tamura,
  • Akio Higo,
  • Cedric Thomas,
  • Seiji Samukawa,
  • Akihiro Murayama

DOI
https://doi.org/10.1063/1.4897958
Journal volume & issue
Vol. 4, no. 10
pp. 107112 – 107112-7

Abstract

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We demonstrate the effect of artificial lateral quantum confinement on exciton-spin relaxation in a GaAs electronic system. GaAs nanodisks (NDs) were fabricated from a quantum well (QW) by top-down nanotechnology using neutral-beam etching aided by protein-engineered bio-nano-templates. The exciton-spin relaxation time was 1.4 ns due to ND formation, significantly extended compared to 0.44 ns for the original QW, which is attributed to weakening of the hole-state mixing in addition to freezing of the carrier momentum. The temperature dependence of the spin-relaxation time depends on the ND thickness, reflecting the degree of quantum confinement.