title: Attempts to grow optically coupled Fibonacci-spaced InGaAs/GaAs quantum wells result in surface gratings.
abstract: An instability in the growth of nonperiodic InGaAs/GaAs multiple quantum well samples, ordinarily of high-quality when grown with equal periods of order of half the wavelength of light in the material, leads to a dramatic microscopic, self-organized surface grating. This effect was discovered while growing quantum wells with two unequal barrier lengths arranged in a Fibonacci sequence to form an optical quasicrystal. A laser beam incident normal to the surface of the sample is diffracted into a propeller-shaped pattern. The sample surface has a distinctly cloudy appearance when viewed along one crystal axis but is mirror-like when the sample is rotated 90 degrees. The instability results in a five-fold increase in the absorption linewidth of the heavy-hole exciton transition. Atomic force microscopy, transmission electron microscopy, and scanning electron microscopy were used to study the samples.
authors.affiliation: College of Optical Sciences, The University of Arizona, Tucson, AZ 85721, USA. brichards@optics.arizona.edu
authors.forename: B C
authors.initials: BC
authors.lastname: Richards
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authors.lastname: Hendrickson
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authors.lastname: Sweet
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authors.lastname: Khitrova
authors.forename: D
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authors.lastname: Litvinov
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authors.lastname: Gerthsen
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authors.lastname: Myer
authors.forename: S
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authors.lastname: Pau
authors.forename: D
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authors.lastname: Sarid
authors.forename: M
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authors.lastname: Wegener
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authors.lastname: Ivchenko
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authors.lastname: Poddubny
authors.forename: H M
authors.initials: HM
authors.lastname: Gibbs