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Your search keyword '"Couto, O. D. D."' showing total 3 results
Start Over Author "Couto, O. D. D." Topic quantum wells
3 results on '"Couto, O. D. D."'

1. Electronic channels for acoustic transport in semiconductor heterostructures.

Author

Biermann, K., Couto, O. D. D., Seidel, W., Hey, R., and Santos, P. V.

Subjects
*ELECTRON transport, *SEMICONDUCTORS, *HETEROSTRUCTURES, *PLASMA waveguides, *QUANTUM wells, *PIEZOELECTRIC devices
Abstract

We demonstrate electronic waveguides for the ambipolar transport of electrons and holes by surface acoustic waves (SAWs) in buried (Al,Ga)As quantum well (QW) structures, which do not require deep-etching for their fabrication. They are defined by tailoring the SAW-induced piezoelectric potential in the QW plane using thin metal stripes deposited onto the piezoelectric cap layer of the QW sample. Acoustic transport experiments show the enhanced capture and acoustic transport of photoexcited carriers underneath the metallic surface stripes. [ABSTRACT FROM AUTHOR]

Published
2010
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2. Acoustically-driven Single Photon Sources on (311)A GaAs.

Author

Lazic, S., Couto, O. D. D., Iikawa, F., Stotz, J. A. H., Hey, R., and Santos, P. V.

Subjects
*GALLIUM arsenide semiconductors, *PHOTONS, *ACOUSTIC surface waves, *QUANTUM wells, *NANOWIRES, *PHOTOLITHOGRAPHY, *ELECTRONIC structure, *FORCE & energy
Abstract

We employ surface acoustic waves to control the transfer of photo-generated carriers between interconnected quantum wells and wires grown on pre-patterned (311)A GaAs substrates. The wires are embedded at photo-lithographically defined positions within (Al,Ga)As/GaAs quantum well. Optical studies on these structures have shown sharp PL lines and antibunched photons with tunable emission energy, revealing the presence of several recombination centers within the wire. The spatial separation of these recombination centers emitting single photons is determined from time-resolved measurements. [ABSTRACT FROM AUTHOR]

Published
2011
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3. Long-range spin transport in (110) GaAs quantum wells.

Author

Couto, O. D. D., Iikawa, F., Rudolph, J., Hey, R., Santos, P. V., and Ploog, K. H.

Subjects
*QUANTUM wells, *GALLIUM, *MAGNETIC fields, *EXCITON theory, *PHYSICS
Abstract

We report on long-range (>60 μm) coherent spin transport via surface acoustic waves in (110) GaAs quantum wells. The long transport distances, attributed to the quenching of the exciton exchange interaction and to the inhibition of the D’yakonov Perel’ spin relaxation mechanism, allow the manipulation of the electron spin during the acoustic transport via external magnetic fields. Potential applications include for quantum information processing. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2007
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