Optical shaping of the polarization anisotropy in a laterally coupled quantum dot dimer

Title
Optical shaping of the polarization anisotropy in a laterally coupled quantum dot dimer
Authors
송진동Heedae KimKwangseuk KyhmRobert A. TaylorJong Su KimSungkyun Park
Keywords
laterally coupled quantum dot; droplet epitaxy; polarization anisotropy; Optical shaping
Issue Date
2020-06
Publisher
Light: Science and Applications
Citation
VOL 9, 100
Abstract
We find that the emission from laterally coupled quantum dots is strongly polarized along the coupled direction [110], and its polarization anisotropy can be shaped by changing the orientation of the polarized excitation. When the nonresonant excitation is linearly polarized perpendicular to the coupled direction [110], excitons (X1 and X2) and local biexcitons (X1X1 and X2X2) from the two separate quantum dots (QD1 and QD2) show emission anisotropy with a small degree of polarization (10%). On the other hand, when the excitation polarization is parallel to the coupled direction [1 10], the polarization anisotropy of excitons, local biexcitons, and coupled biexcitons (X1X2) is enhanced with a degree of polarization of 74%. We also observed a consistent anisotropy in the time-resolved photoluminescence. The decay rate of the polarized photoluminescence intensity along the coupled direction is relatively high, but the anisotropic decay rate can be modified by changing the orientation of the polarized excitation. An energy difference is also observed between the polarized emission spectra parallel and perpendicular to the coupled direction, and it increases by up to three times by changing the excitation polarization orientation from [110] to [110]. These results suggest that the dipole?dipole interaction across the two separate quantum dots is mediated and that the anisotropic wavefunctions of the excitons and biexcitons are shaped by the excitation polarization.
URI
http://pubs.kist.re.kr/handle/201004/72120
ISSN
2047-7538
Appears in Collections:
KIST Publication > Article
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE