title: Exciton Dipole-Dipole Interaction in a Single Coupled-Quantum-Dot Structure via Polarized Excitation.
abstract: We find that the exciton dipole-dipole interaction in a single laterally coupled GaAs/AlGaAs quantum dot structure can be controlled by the linear polarization of a nonresonant optical excitation. When the excitation intensity is increased with the linearly polarized light parallel to the lateral coupling direction [11̅0], excitons (X1and X2) and local biexcitons (X1X1and X2X2) of the two separate quantum dots (QD1and QD2) show a redshift along with coupled biexcitons (X1X2), while neither coupled biexcitons nor a redshift are observed when the polarization of the exciting beam is perpendicular to the coupling direction. The polarization dependence and the redshift are attributed to an optical nonlinearity in the exciton Förster resonant energy transfer interaction, whereby exciton population transfer between the two quantum dots also becomes significant with increasing excitation intensity. We have further distinguished coupled biexcitons from local biexcitons by their large diamagnetic coefficient.
authors.affiliation: Department of Opto-mechatronics and Cogno-mechatronics, RCDAMP, Pusan National University , Busan 609-735, Republic of Korea.|Clarendon Laboratory, Department of Physics, University of Oxford , Oxford, OX1 3PU, United Kingdom.
authors.forename: Heedae
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Opto-mechatronics and Cogno-mechatronics, RCDAMP, Pusan National University , Busan 609-735, Republic of Korea.
authors.forename: Inhong
authors.initials: I
authors.lastname: Kim
authors.affiliation: Department of Opto-mechatronics and Cogno-mechatronics, RCDAMP, Pusan National University , Busan 609-735, Republic of Korea.
authors.forename: Kwangseuk
authors.initials: K
authors.lastname: Kyhm
authors.affiliation: Clarendon Laboratory, Department of Physics, University of Oxford , Oxford, OX1 3PU, United Kingdom.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Taylor
authors.affiliation: Department of Physics, Yeungnam University , Gyeongsan, 712-749, Republic of Korea.
authors.forename: Jong Su
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Nano-Photonics Research Center, KIST , Seoul, 136-791, Republic of Korea.
authors.forename: Jin Dong
authors.initials: JD
authors.lastname: Song
authors.affiliation: College of Liberal Arts and Sciences, Anyang University , Gyeonggi-do 430-714, South Korea.
authors.forename: Koo Chul
authors.initials: KC
authors.lastname: Je
authors.affiliation: Department of NANOscience, Institut Néel, CNRS , rue des Martyrs 38054, Grenoble, France.
authors.forename: Le Si
authors.initials: LS
authors.lastname: Dang
keywords: FRET; Laterally coupled quantum dot structures; coupled biexcitons; dipole−dipole interaction