Optical anisotropy of (001)-GaAs surface quantum wells

• We report a reflectance difference spectroscopy (RDS) study of the optical anisotropy of GaAs:(001) surface quantum wells consisting of a thin GaAs layer (3-30 nm thick) embedded between an arsenic reconstructed surface and an AlAs barrier. The RDS spectra display anisotropic contributions from the free surface and from the GaAs/AlAs interface. By comparing RDS spectra for the c(4×4) and (2×4) surface reconstructions, we separate these two contributions, and demonstrate that the anisotropy around the E1 and E1+Δ1 transitions comprises a component originating from modifications of bulk states near the surface. The latter is attributed to anisotropic strains induced by the surface reconstruction. The experimental data are well described by a model for the RDS response of the multilayer structures, which also takes into account the blue energy shifts and the changes in oscillator strength of the E1 and E1+Δ1 transitions induced by quantum-well confinement.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

arsenic; gallium arsenide

anisotropy; article; energy; optics; oscillator; quantum mechanics; reflectometry; surface property

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)