%0 Journal Article
%A Dey, Arka Bikash
%A Sanyal, Milan
%A Schropp, Andreas
%A Achiles, Silvio
%A Keller, Thomas F.
%A Farrer, Ian
%A Ritchie, David A.
%A Bertram, Florian
%A Schroer, Christian
%A Seeck, Oliver
%T Culling a self-assembled quantum dot as a single-photon source using X-ray microscopy
%J ACS nano
%V 17
%N 16
%@ 1936-0851
%C Washington, DC
%I Soc.
%M PUBDB-2022-05258
%P 16080 - 16088
%D 2023
%Z The paper is published in "ASAP" category, the volume number and page number are yet to come. The DOI number is already assigned.
%X Epitaxially grown self-assembled semiconductor quantum dots (QDs) with atom-like optical properties, have emerged as the best choice for single photon sources required for the development of quantum technology and quantum networks. Nondestructive selection of a single QD having desired structural, compositional, and optical characteristics is essential to obtain noise-free, fully indistinguishable single or entangled photons out of single-photon emitters. Here, we show that the structural-orientations and local compositional-inhomogeneities within a single QD and the surrounding wet-layer can be probed in a screening fashion by scanning X-ray diffraction microscopy (SXDM) and X-ray fluorescence (XRF) with a few tens of nanometers-sized synchrotron radiation-beam. The presented measurement protocol can be used to cull the best single QD from the enormous number of self-assembled dots grown simultaneously. The results obtained show that the elemental composition and resultant strain profiles of a QD are sensitive to in-plane crystallographic directions. We also observe that lattice expansion after a certain composition-limit introduces shear strain within a QD, enabling the possibility of controlled chiral-QD formation. Nanoscale-chirality and compositional-anisotropy, contradictory to common assumption, need to be incorporated into existing theoretical models to predict the optical properties of single-photon sources and to further tune the epitaxial growth process of self-assembled quantum structures.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ 37523736
%U <Go to ISI:>//WOS:001040500800001
%R 10.1021/acsnano.3c04835
%U https://bib-pubdb1.desy.de/record/483355