Table Of ContentQuantum Dots:Fundamentals, Applications,
and Frontiers
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Series II:Mathematics,Physics and Chemistry – Vol.190
Quantum Dots: Fundamentals,
Applications, and Frontiers
edited by
Bruce A.Joyce
The Blackett Laboratory,
Imperial College London, U.K.
Pantelis C.Kelires
Physics Department, University of Crete, Heraclion, Crete, Greece
and Foundation for Research and Technology-Hellas (FORTH),
Heraclion, Crete, Greece
Anton G.Naumovets
National Academy of Sciences of Ukraine,
Institute of Physics, Kiev, Ukraine
and
Dimitri D. Vvedensky
The Blackett Laboratory,
Imperial College London, U.K.
“British Association of Crystal Growth”
Published in cooperation with NATO Public Diplomacy Division
Proceedings of the NATO Advanced Research Workshop on
Quantum Dots:Fundamentals, Applications and Frontiers
Crete, Greece ,
20 24 July 2003
A C.I.P.Catalogue record for this book is available from the Library of Congress.
ISBN 10 1-4020-3314-1 (PB) Springer Dordrecht, Berlin, Heidelberg, New York
ISBN 13 978-1-4020-3314-8 (PB) Springer Dordrecht, Berlin, Heidelberg, New York
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ISBN 13 978-1-4020-3314-1 (HB) Springer Dordrecht, Berlin, Heidelberg, New York
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CONTENTS
Preface ix
List of Contributors xi
Atomistic Processes during Quantum Dot Formation
QuantumDotsintheInAs/GaAsSystem:AnOverviewoftheirFormation 1
B.A.JoyceandD.D.Vvedensky
First-PrinciplesStudyofInAs/GaAs(001)Heteroepitaxy 27
E.PenevandP.Kratzer
FormationofTwo-DimensionalSi/GeNanostructuresObservedbySTM 43
B.Voigtla¨¨nder
Diffusion,NucleationandGrowthonMetalSurfaces 55
O.Biham,I.Furman,H. Mehl andJ.F.Wendelken
The Stranski–Krastanov Transition
71
TheMechanismoftheStranski–KrastanovTransition
A.G.Cullis,D.J.Norris,T.Walther,M.A.Migliorato,andM.Hopkinson
Off-latticeKMCSimulationsofStranski-Krastanov-LikeGrowth 89
M.BiehlandF.Much
TemperatureRegimesofStrain-InducedInAsQuantumDotFormation 103
C.HeynandA.Bolz
KineticModellingofStrainedFilms: EffectsofWettingandFacetting 121
D.KandelandH.R.Eisenberg
Ge/SiNanostructureswithQuantumDotsgrownbyIon-Beam-Assisted 135
Heteroepitaxy
A.V.Dvurechenskii,J.V.Smagina,V.A.Armbrister,V.A.Zinovyev,
P.L.Novikov,S.A.Teys,andR.Groetzschel
v
vi
Self-Assembly of Quantum Dot Arrays
LateralOrganizationofQuantumDotsonaPatternedSubstrate 145
C.Priester
SomeThermodynamicAspectsofSelf-Assemblyof Quantum Dot 157
Arrays
J.E.PrietoandI.Markov
TheSearchforMaterialswithSelf-AssemblingProperties: TheCaseof 173
Si-basedNanostructures
I.Goldfarb
Structure and Composition of Quantum Dots
X-RayScatteringMethodsfortheStudyofEpitaxialSelf-Assembled 183
QuantumDots
J.Stangl,T.Schu¨¨lli,A.Hesse,G.Bauer,andV.Holy´
Carbon-InducedGeDotsonSi(100): InterplayofStrainandChemical 209
Effects
G.Hadjisavvas,Ph. Sonnet,andP.C.Kelires
GrowthInformationCarriedbyReflectionHigh-EnergyElectron 221
Diffraction
A´. Nemcsics
Electrons and Holes in Quantum Dots
EfficientCalculationofElectronStatesinSelf-AssembledQuantum 239
Dots: ApplicationtoAugerRelaxation
D.Chaney,M.Roy,andP.A.Maksym
QuantumDotMoleculesandChains 257
W.Jasko´lski,M.Zielin´´ski,A.Stro´´z˙ecka,G.W.Bryant,andJ.Aizpurua
CollectivePropertiesofElectronsandHolesinCoupledQuantumDots 269
G.Goldoni,F.Troiani,M.Rontani,D.Bellucci,E.Molinari,and
U.Hohenester
vii
PhaseTransitionsinWignerMolecules 285
J.Adamowski,B.Szafran,andS.Bednarek
FastControlofQuantumStatesinQuantumDots: Limitsdueto 301
Decoherence
L.Jacak,P.Machnikowski,andJ.Krasnyj
Optical Properties of Quantum Dots
RealSpaceAbInitioCalculationsofExcitationEnergiesinSmall 317
SiliconQuantumDots
A.D.Zdetsis,C.S.Garoufalis,andS.Grimme
GeSi/Si(001)StructureswithSelf-AssembledIslands: Growthand 333
OpticalProperties
N.V.Vostokov,Yu. N.Drozdov,D.N.Lobanov,A.V.Novikov,
M.V.Shaleev,A.N.Yablonskii,Z.F.Krasilnik,A.N.Ankudinov,
M.S.Dunaevskii,A.N.Titkov,P.Lytvyn,V.U.Yukhymchuk,and
M.Ya. Valakh
QuantumDotsinHighElectricFields: FieldandPhotofieldEmission 353
fromGeNanoclustersonSi(100)
A.A.Dadykin,A.G.Naumovets,Yu. N.Kozyrev,M.Yu. Rubezhanska,
andYu. M.Litvin
OpticalEmissionBehaviorofSiQuantumDots 369
X.ZianniandA.G.Nassiopoulou
Strain-DrivenPhenomenauponOvergrowthofQuantumDots: 377
ActivatedSpinodalDecompositionandDefectReduction
M.V.MaximovandN.N.Ledentsov
Preface
The morphology that results during the growth of a material on the substrate of
a different material is central to the fabrication of all quantum heterostructures.
Thismorphologyisdeterminedbyseveralfactors,includingthemannerinwhich
strain is accommodated if the materials have different lattice constants. One of
themosttopicalmanifestationsoflatticemisfitistheformationofcoherentthree-
dimensional(3D)islandsduringtheStranski–Krastanovgrowthofahighly-strained
system. TheprototypicalcasesareInAsonGaAs(001)andGeonSi(001),though
othermaterialscombinationsalsoexhibitthisphenomenon. Whenthe3Dislands
are embedded within epitaxial layers of a material that has a wider band gap, the
carrierswithintheislandsareconfinedbythepotentialbarriersthatsurroundeach
island,forminganarrayofquantumdots(QDs).
Suchstructureshavebeenproducedforbothbasicphysicsstudiesanddevicefabri-
cation,includingQDlasersandlight-emittingdiodes(LEDs)operatingatthecom-
mercially important wavelengths of 1.3 µm and 1.55 µm. On a more speculative
level,QDensembleshavebeensuggestedasapossiblepathwayforthesolid-state
implementationofaquantumcomputer. Althoughsomeoftheprinciplesofquan-
tumcomputinghavebeenverifiedbyothermeans, thepracticalutilizationofthis
newcomputing paradigm may warrant some sortof solid state architecture. QDs
areseenaspossiblecomponentsofsuchacomputer,asevidencedbyanumberof
papersappearingintheliteratureproposingQD-basedarchitecturesandworkshops
thatarebeingorganizedtoexplorethesepossibilities.
Inviewofmanydevelopmentsonseveralfronts,aworkshoptobringtogetherex-
perimentalistsandtheoristsfromvariousdisciplinestostimulateinterdisciplinary
cross-fertilization,toreviewrecentprogressandremainingchallenges,andtodis-
cusscommonproblemsandsolutions,wasviewedasbeingparticularlytimely. The
ScientificAffairsDivisionofNATO,underitsAdvancedResearchWorkshoppro-
gram,andtheBritishAssociationofCrystalGrowth,kindlyagreedtosupportsuch
ameeting. Entitled“QuantumDots:Fundamentals, Applications, andFrontiers”,
thisARWwasheldattheSantaMarinaBeachHotelinAmmoudara,Cretebetween
20–24July,2003. Thethemeswerethefundamentalsofthegrowth,structure,and
propertiesofquantumdots,theirapplicationsindevices,andtheirpossiblefuture
uses. Themainemphasiswastheidentificationofthefactorsthatlimittheutiliza-
tionofquantumdotsinapplicationsandpossiblestrategiesbywhichthesecanbe
overcome. ThisARWhighlightedthefollowingkeyissues:
ix
x
• ThemechanismofquantumdotformationduringStranski–Krastanovgrowth
isacomplexprocess,withmanykeyfactorsthatarestillnotcompletelyunder-
stoodattheatomisticlevel,includingtheformationkinetics,themorphological
evolutionofdots(“precursors”and“pyramids”), andchangescausedbycap-
ping.
• The role of atomistic and continuum modelling is becoming increasingly im-
portantinaddressingtheseissues,withseveralspeakersdescribingmodelsthat
reproduceseveralimportantaspectsofStranski–Krastanovgrowth.
• Therearetheoreticalandcomputationtoolsavailabletodeterminetheelectronic
propertiesofquantumdots,butthedependenceonshapeandcompositionoften
inhibitstheabilitytoreachunequivocalconclusions.
• Despitetheexperimentaluncertaintiesaboutfundamentalsteps,thecontrolled
growthofquantum dotsisalready leading toanumberofpromising applica-
tions,includinglasersandsingle-photondetectors.
• Quantumcomputingbasedonaquantumdotarchitectureisapossibility,even
if confined to low temperatures, with the scalability and large confinement
energiesbeingparticularlyattractivefeatures. Fordetrimentaleffects,suchas
decoherenceduetophonons,plausiblesolutionshavebeenproposed.
Thepresentvolumecontainstheproceedingsofthisstimulatingmeeting. The
organizers are deeply thankful to the Scientific Affairs Committee of NATO and
the British Association of Crystal Growth for their sponsorship and enthusiastic
endorsementofthismeeting.
BruceA.Joyce
PantelisC.Kelires
AntonG.Naumovets
DimitriD.Vvedensky
