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Comment: 7 pages, including 4 figures Changes made to introduction Added
figure Submitted to SSC
Comment: Accepted for publication on Physical Review B Rapid Communications
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.
Comment: 9 pages, 3 figures. Submitted to Applied Physics Letters
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.
Comment: 5 pages, 3 figures
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.
