Spin polarization of the neutral exciton in a single quantum dot

被引：1

作者：

Moskalenko, E. S. ^{[1
,2
]}

Larsson, L. A. ^{[1
]}

Holtz, P. O. ^{[1
]}

机构：

[1] Linkoping Univ, IFM, S-58183 Linkoping, Sweden

[2] Russian Acad Sci, AF Ioffe Phy Tech Inst, St Petersburg 196140, Russia

来源：

SUPERLATTICES AND MICROSTRUCTURES | 2011年 / 49卷 / 03期

关键词：

Quantum dot; Exciton; Polarization; Photoluminescence; Spin; OPTICAL ORIENTATION;

D O I：

10.1016/j.spmi.2010.06.012

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

While efficient nuclear polarization has earlier been reported for the charged exciton in InAs/GaAs quantum dots at zero external magnetic field, we report here on a surprisingly high degree of circular polarization, up to approximate to 60%, for the neutral exciton emission in individual InAs/GaAs dots. This high degree of polarization is explained in terms of the appearance of an effective nuclear magnetic field which stabilizes the electron spin. The nuclear polarization is manifested in experiments as a detectable Overhauser shift. In turn, the nuclei located inside the dot are exposed to an effective electron magnetic field, the Knight field. This nuclear polarization is understood as being due to the dynamical nuclear polarization by an electron localized in the QD. The high degree of polarization for the neutral exciton is also suggested to be due to separate in-time capture of electrons and holes into the QD. (C) 2010 Elsevier Ltd. All rights reserved.

引用

页码：294 / 299

页数：6

共 21 条

[1] Fine structure of neutral and charged excitons in self-assembled In(Ga)As/(Al)GaAs quantum dots -: art. no. 195315 [J].

Bayer, M ;

Ortner, G ;

Stern, O ;

Kuther, A ;

Gorbunov, AA ;

Forchel, A ;

Hawrylak, P ;

Fafard, S ;

Hinzer, K ;

Reinecke, TL ;

Walck, SN ;

Reithmaier, JP ;

Klopf, F ;

Schäfer, F .

PHYSICAL REVIEW B, 2002, 65 (19) :1953151-19531523

[2] Optical pumping of the electronic and nuclear spin of single charge-tunable quantum dots [J].

Bracker, AS ;

Stinaff, EA ;

Gammon, D ;

Ware, ME ;

Tischler, JG ;

Shabaev, A ;

Efros, AL ;

Park, D ;

Gershoni, D ;

Korenev, VL ;

Merkulov, IA .

PHYSICAL REVIEW LETTERS, 2005, 94 (04) :1-4

[3] Bistability of the nuclear polarization created through optical pumping in In1-xGaxAs quantum dots [J].

Braun, P. -F. ;

Urbaszek, B. ;

Amand, T. ;

Marie, X. ;

Krebs, O. ;

Eble, B. ;

Lemaitre, A. ;

Voisin, P. .

PHYSICAL REVIEW B, 2006, 74 (24)

[4] Direct observation of the electron spin relaxation induced by nuclei in quantum dots [J].

Braun, PF ;

Marie, X ;

Lombez, L ;

Urbaszek, B ;

Amand, T ;

Renucci, P ;

Kalevich, VK ;

Kavokin, KV ;

Krebs, O ;

Voisin, P ;

Masumoto, Y .

PHYSICAL REVIEW LETTERS, 2005, 94 (11)

[5] Determination of interface preference by observation of linear-to-circular polarization conversion under optical orientation of excitons in type-II GaAs/AlAs superlattices [J].

Dzhioev, RI ;

Gibbs, HM ;

Ivchenko, EL ;

Khitrova, G ;

Korenev, VL ;

Tkachuk, MN ;

Zakharchenya, BP .

PHYSICAL REVIEW B, 1997, 56 (20) :13405-13413

[6] Dynamic nuclear polarization of a single charge-tunable InAs/GaAs quantum dot [J].

Eble, B. ;

Krebs, O. ;

Lemaitre, A. ;

Kowalik, K. ;

Kudelski, A. ;

Voisin, P. ;

Urbaszek, B. ;

Marie, X. ;

Amand, T. .

PHYSICAL REVIEW B, 2006, 74 (08)

[7] Electron and nuclear spin interactions in the optical spectra of single GaAs quantum dots [J].

Gammon, D ;

Efros, AL ;

Kennedy, TA ;

Rosen, M ;

Katzer, DS ;

Park, D ;

Brown, SW ;

Korenev, VL ;

Merkulov, IA .

PHYSICAL REVIEW LETTERS, 2001, 86 (22) :5176-5179

[8] Energy relaxation by multiphonon processes in InAs/GaAs quantum dots [J].

Heitz, R ;

Veit, M ;

Ledentsov, NN ;

Hoffmann, A ;

Bimberg, D ;

Ustinov, VM ;

Kopev, PS ;

Alferov, ZI .

PHYSICAL REVIEW B, 1997, 56 (16) :10435-10445

[9]

IVCHENKO EL, 1995, PURE APPL CHEM, V67, P463, DOI 10.1117/12.200991

[10] Dynamic self-polarization of nuclei in low-dimensional systems [J].

Korenev, VL .

JETP LETTERS, 1999, 70 (02) :129-134

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