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Author Nowak, M.P.; Szafran, B.; Peeters, F.M.
Title Manipulation of two-electron states by the electric field in stacked self-assembled dots Type A1 Journal article
Year 2008 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 20 Issue 39 Pages 395225,1-395225,14
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A pair of electrons in vertically stacked self-assembled quantum dots is studied and the singlettriplet energy splitting is calculated in an external electric field using the configuration-interaction method. We show that for double quantum dots the dependence of the singlet energy levels on the electric field involves multiple avoided crossings of three energy levels. The exchange interaction, i.e., the energy difference of the lowest triplet and lowest singlet states, can be tuned by an electric field in a wide range of several tens of meV. For electric fields exceeding a threshold value the exchange interaction becomes a linear function of the field when the two electrons in the singlet state start to occupy the same dot. We also consider non-symmetric confinement, non-perfectly aligned dots, in horizontal as well as vertical field orientation. In a stack of three vertically coupled dots the depth of the confinement in the central dot can be used to enhance the exchange interaction. For a deeper central dot the dependence of the exchange interaction on the electric field is anomalousit initially decreases when the field is applied in both directions parallel and antiparallel to the axis of the stack. Such a behavior is never observed for a pair of quantum dots.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000259034200032 Publication Date 2008-09-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 5 Open Access
Notes Approved Most recent IF: 2.649; 2008 IF: 1.900
Call Number UA @ lucian @ c:irua:76592 Serial 1940
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Author Szafran, B.; Peeters, F.M.; Bednarek, S.; Adamowski, J.
Title Exact broken-symmetry states and Hartree-Fock solutions for quantum dots at high magnetic fields Type A1 Journal article
Year 2005 Publication Physica. E: Low-dimensional systems and nanostructures T2 – 3rd International Conference on Quantum Dots (QD 2004), MAY 10-13, 2004, Max Bell Bldg Banff Ctr, Banff, Canada Abbreviated Journal Physica E
Volume 26 Issue 1-4 Pages 252-256
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Wigner molecules formed at high magnetic fields in circular and elliptic quantum dots are studied by exact diagonalization (ED) and unrestricted Hartree-Fock (UHF) methods with multicenter basis of displaced lowest Landau level wave functions. The broken symmetry states with semi-classical charge density constructed from superpositions of the ED solutions are compared to the UHF results. UHF overlooks the dependence of the few-electron wave functions on the actual relative positions of electrons localized in different charge puddles and partially compensates for this neglect by an exaggerated separation of charge islands which are more strongly localized than in the exact broken-symmetry states. (C) 2004 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher North-Holland Place of Publication Amsterdam Editor
Language Wos 000227249000053 Publication Date 2004-12-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1386-9477; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.221 Times cited 2 Open Access
Notes Approved Most recent IF: 2.221; 2005 IF: 0.946
Call Number UA @ lucian @ c:irua:103181 Serial 1105
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Author Chwiej, T.; Bednarek, S.; Adamowski, J.; Szafran, B.; Peeters, F.M.
Title Coulomb-interaction driven anomaly in the Stark effect for an exciton in vertically coupled quantum dots Type A1 Journal article
Year 2005 Publication Journal of luminescence T2 – 6th International Conference on Excitonic Processes in Condensed Matter, (EXCON 04), JUL 06-09, 2004, Cracow, POLAND Abbreviated Journal J Lumin
Volume 112 Issue 1-4 Pages 122-126
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The effect of the electric field on an exciton confined in a pair of vertically coupled quantum dots is studied. We use a single-band approximation and a parabolic model potential. As a result of these idealizations, we obtain a numerically solvable model, which is used to describe the influence of the electron-hole interaction on the Stark effect for the lowest-energy photo luminescence lines. We show that for intermediate tunnel coupling between the dots this interaction leads to an anomalous Stark effect with an essential deviation of the recombination energy from the usual quadratic dependence on the electric field. (c) 2004 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000228439600029 Publication Date 2004-12-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2313; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.686 Times cited 10 Open Access
Notes Approved Most recent IF: 2.686; 2005 IF: 1.518
Call Number UA @ lucian @ c:irua:103675 Serial 532
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Author Peeters, F.M.; Szafran, B.; Chwiej, T.; Bednarek, S.; Adamowski, J.
Title Stability of charged exciton states in quantum wires Type A1 Journal article
Year 2006 Publication Few-body systems Abbreviated Journal Few-Body Syst
Volume 38 Issue 2/4 Pages 121-124
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Wien Editor
Language Wos 000238498200013 Publication Date 2006-05-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0177-7963;1432-5411; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.877 Times cited 3 Open Access
Notes Approved Most recent IF: 0.877; 2006 IF: 0.765
Call Number UA @ lucian @ c:irua:60035 Serial 3125
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