16628
2016
eng
063011
18
article
1
2018-08-01
--
--
Mode-switching induced super-thermal bunching in quantum-dot microlasers
The super-thermal photon bunching in quantum-dot (QD) micropillar lasers is investigated both experimentally and theoretically via simulations driven by dynamic considerations. Using stochastic multi-mode rate equations we obtain very good agreement between experiment and theory in terms of intensity profiles and intensity-correlation properties of the examined QD micro-laser's emission. Further investigations of the time-dependent emission show that super-thermal photon bunching occurs due to irregular mode-switching events in the bimodal lasers. Our bifurcation analysis reveals that these switchings find their origin in an underlying bistability, such that spontaneous emission noise is able to effectively perturb the two competing modes in a small parameter region. We thus ascribe the observed high photon correlation to dynamical multistabilities rather than quantum mechanical correlations.
New Journal of Physics
10.1088/1367-2630/18/6/063011
urn:nbn:de:bvb:20-opus-166286
New Journal of Physics 18(2016)063011. DOI: 10.1088/1367-2630/18/6/063011
615613
false
true
Christoph Redlich
Benjamin Lingnau
Steffen Holzinger
Elisabeth Schlottmann
Sören Kreinberg
Christian Schneider
Martin Kamp
Sven Höfling
Janik Wolters
Stephan Reitzenstein
Kathy Lüdge
eng
uncontrolled
microlaser
eng
uncontrolled
nonlinear dynamics
eng
uncontrolled
correlation properties
eng
uncontrolled
photon statistics
eng
uncontrolled
noise and multimode dynamics
eng
uncontrolled
quantum dot laser
Physik
open_access
Physikalisches Institut
OpenAIRE
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/16628/Redlich_New_Journal_of_Physics.pdf
11676
2014
eng
043003
16
article
1
2015-07-25
--
--
Free space quantum key distribution over 500 meters using electrically driven quantum dot single-photon sources-a proof of principle experiment
Highly efficient single-photon sources (SPS) can increase the secure key rate of quantum key distribution (QKD) systems compared to conventional attenuated laser systems. Here we report on a free space QKD test using an electrically driven quantum dot single-photon source (QD SPS) that does not require a separate laser setup for optical pumping and thus allows for a simple and compact SPS QKD system. We describe its implementation in our 500 m free space QKD system in downtown Munich. Emulating a BB84 protocol operating at a repetition rate of 125 MHz, we could achieve sifted key rates of 5-17 kHz with error ratios of 6-9% and g((2))(0)-values of 0.39-0.76.
New Journal of Physics
10.1088/1367-2630/16/4/043003
urn:nbn:de:bvb:20-opus-116760
New Journal of Physics 16 (2014) 043003. doi:10.1088/1367-2630/16/4/043003
Wilhelm-Conrad-Röntgen-Forschungszentrum für komplexe Materialsysteme
Markus Rau
Tobias Heindel
Sebastian Unsleber
Tristan Braun
Julian Fischer
Stefan Frick
Sebastian Nauerth
Christian Schneider
Gwenaelle Vest
Stephan Reitzenstein
Martin Kamp
Alfred Forchel
Sven Höfling
Harald Weinfurter
eng
uncontrolled
QKD
eng
uncontrolled
electrically driven
eng
uncontrolled
free space
eng
uncontrolled
quantum dots
eng
uncontrolled
quantum key distribution
Physik
open_access
Physikalisches Institut
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/11676/092_Rau_NEW_JOURNAL_OF_PHYSICS.pdf
22860
2019
eng
28816-28831
20
27
article
1
2021-03-02
--
--
Stochastic polarization switching induced by optical injection in bimodal quantum-dot micropillar lasers
Mutual coupling and injection locking of semiconductor lasers is of great interest in non-linear dynamics and its applications for instance in secure data communication and photonic reservoir computing. Despite its importance, it has hardly been studied in microlasers operating at mu W light levels. In this context, vertically emitting quantum dot micropillar lasers are of high interest. Usually, their light emission is bimodal, and the gain competition of the associated linearly polarized fundamental emission modes results in complex switching dynamics. We report on selective optical injection into either one of the two fundamental mode components of a bimodal micropillar laser. Both modes can lock to the master laser and influence the non-injected mode by reducing the available gain. We demonstrate that the switching dynamics can be tailored externally via optical injection in very good agreement with our theory based on semi-classical rate equations. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Optics Express
10.1364/OE.27.028816
urn:nbn:de:bvb:20-opus-228603
publish
Optics Express Vol. 27, No. 20 | 30 Sep 2019
true
true
CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International
Elisabeth Schlottmann
David Schicke
Felix Krüger
Benjamin Lingnau
Christian Schneider
Sven Höfling
Kathy Lüdge
Xavier Porte
Stephan Reitzenstein
eng
uncontrolled
Nonlinear Dynamics
eng
uncontrolled
Bistability
eng
uncontrolled
Generation
eng
uncontrolled
Subject
eng
uncontrolled
Regimes
eng
uncontrolled
Physics
eng
uncontrolled
Vcsels
Physik
open_access
Physikalisches Institut
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/22860/Stochastic_polarization_switching.pdf
1024
2004
deu
doctoralthesis
1
2005-03-07
--
2004-07-22
Monolithische Halbleiternanostrukturen als ballistische Verstärker und logische Gatter
Ballistic amplifiers and logic gates based on monolithic semiconductor nanostructures
Im Rahmen dieser Arbeit wurden monolithische Halbleiternanostrukturen hinsichtlich neuartiger nanoelektronischer Transporteffekte untersucht. Hierbei wurden gezielt der ballistische Charakter des Ladungstransportes in mesoskopischen Strukturen sowie die kapazitive Kopplung einzelner Strukturbereiche ausgenutzt, um ballistische Verstärkerelemente und logische Gatter zu realisieren. Die untersuchten Nanostrukturen basieren auf dem zweidimensionalen Elektronengas modulationsdotierter GaAs/AlGaAs-Heterostrukturen und wurden über Elektronenstrahl-Lithographie sowie nasschemische Ätztechniken realisiert. Somit entstanden niederdimensionale Leiter mit Kanalbreiten von wenigen 10 nm, deren Leitwert über planare seitliche Gates elektrisch kontrolliert werden kann. Bei den Transportuntersuchungen, die zum Teil im stark nichtlinearen Transportbereich und bei Temperaturen bis hin zu 300 K durchgeführt wurden, stellte sich das Konzept verzweigter Kanalstrukturen als vielversprechend hinsichtlich der Anwendung für eine neuartige Nanoelektronik heraus. So kann eine im Folgenden als Y-Transistor bezeichnete, verzweigte Kanalstruktur in Abhängigkeit der äußeren Beschaltung als Differenzverstärker, invertierender Verstärker, bistabiles Schaltelement oder aber auch als logisches Gatter eingesetzt werden. Zudem eröffnet der Y-Transistor einen experimentellen Zugang zu den nichtklassischen Eigenschaften nanometrischer Kapazitäten, die sich von denen rein geometrisch definierter Kapazitäten aufgrund der endlichen Zustandsdichte erheblich unterscheiden können. Für ballistische Y-Verzweigungen tritt zudem ein neuartiger Gleichrichtungseffekt auf, der in Kombination mit den verstärkenden Eigenschaften von Y-Transistoren dazu genutzt wurde, kompakte logische Gatter sowie einen ballistischen Halb-Addierer zu realisieren.
This thesis reports investigations of monolithic semiconductor nanostructures with novel nanoelectronic transport effects. In particular, it is shown that the ballistic motion of electrons in nanoelectronic devices in combination with capacitive coupling of nearby device sections can be used to realize ballistic amplifiers and logic gates. The nanostructures under investigation are based on the two dimensional electron gas of modulation doped GaAs/AlGaAs-heterostructures and were patterned by electron-beam-lithography and wet chemical etching. In this way, low dimensional conductors with widths on the order of a few 10 nm to about 100 nm controlled by in-plane gates were realized. Investigations at temperatures up to 300 K in the nonlinear transport regime show that branched nanojunctions are promising candidates for future nanoelectronic building blocks. Depending on the external circuit, gated Y-branched nanojunctions, here referred to as "Y-transistors", can be used as differential amplifiers, inverting amplifiers, bistable switches and logic gates. In addition, Y-transistors allow the experimental investigation of nonclassical properties of nanoscaled capacitors, which differ significantly from those of macroscopic capacitors due to the different densities of states. Moreover, a novel ballistic rectification effect observed for Y-branched nanojunctions is exploited to realize a ballistic in-plane half-adder with output signals amplified by feedback coupled Y-transistors.
urn:nbn:de:bvb:20-opus-12177
1217
X120024
Stephan Reitzenstein
deu
swd
Transistor
deu
swd
Nanostruktur
deu
swd
Ballistischer Effekt
deu
uncontrolled
Nanostruktur
deu
uncontrolled
Transistor
deu
uncontrolled
Ballistischer Ladungstransport
deu
uncontrolled
Verstärker
deu
uncontrolled
Logisches Gatter
eng
uncontrolled
Nanostructure
eng
uncontrolled
Transistor
eng
uncontrolled
Ballistic Transport
eng
uncontrolled
Amplifier
eng
uncontrolled
Logic Gate
Physik
open_access
Physikalisches Institut
Universität Würzburg
Universität Würzburg
https://opus.bibliothek.uni-wuerzburg.de/files/1024/DissertationSReitzenstein.pdf