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Comment: 7 pages, including 4 figures Changes made to introduction Added figure Submitted to SSC
Electroluminescence emission controlled by means of surface acoustic waves (SAWs) in planar light-emitting diodes (pLEDs) is demonstrated. Interdigital transducers for SAW generation were integrated onto pLEDs fabricated following the scheme which we have recently developed. Current-voltage, light-voltage and photoluminescence characteristics are presented at cryogenic temperatures. We argue that this scheme represents a valuable building block for advanced optoelectronic architectures.
The single-particle energy spectrum of a two-dimensional electron gas in a perpendicular magnetic field consists of equally-spaced spin-split Landau levels, whose degeneracy is proportional to the magnetic field strength. At integer and particular fractional ratios between the number of electrons and the degeneracy of a Landau level (filling factors n) quantum Hall effects occur, characterised by a vanishingly small longitudinal resistance and quantised Hall voltage. The quantum Hall regime offers unique possibilities for the study of cooperative phenomena in many-particle systems under well-controlled conditions. Among the fields that benefit from quantum-Hall studies is magnetism, which remains poorly understood in conventional material. Both isotropic and anisotropic ferromagnetic ground states have been predicted and few of them ...
A surface-acoustic-wave (SAW) driven light-emitting-diode structure that can implement a single-photon-source for quantum-cryptography applications is demonstrated. Our lateral n-i-p junction is realized starting from an undoped GaAs/AlGaAs quantum well by gating. It incorporates interdigitated transducers for SAW generation and lateral gates for current control. We demonstrate acoustoelectric transport and SAW-driven electroluminescence. The acoustoelectric current can be controlled down to complete pinch-off by means of the lateral gates.
We demonstrate anti-bunched emission from a lateral-light emitting diode. Sub-Poissonian emission statistic, with a g$^{(2)}$(0)=0.7, is achieved at cryogenic temperature in the pulsed low-current regime, by exploiting electron injection through shallow impurities located in the diode depletion region. Thanks to its simple fabrication scheme and to its modulation bandwidth in the GHz range, we believe our devices are an appealing substitute for highly-attenuated lasers in existing quantum-key-distribution systems. Our devices outperform strongly-attenuated lasers in terms of multi-photon emission events and can therefore lead to a significant security improvement in existing quantum key distribution systems.
We present a planar laser diode based on a simple fabrication scheme compatible with virtually any geometry accessible by standard semiconductor lithography technique. We show that our lasers exhibit ~1 GHz -3dB-modulation-bandwidth already in this prototypical implementation. Directions for a significant speed increase are discussed.
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