TY  - JOUR
AU  - Dey, Arka Bikash
AU  - Sanyal, Milan
AU  - Schropp, Andreas
AU  - Achiles, Silvio
AU  - Keller, Thomas F.
AU  - Farrer, Ian
AU  - Ritchie, David A.
AU  - Bertram, Florian
AU  - Schroer, Christian
AU  - Seeck, Oliver
TI  - Culling a self-assembled quantum dot as a single-photon source using X-ray microscopy
JO  - ACS nano
VL  - 17
IS  - 16
SN  - 1936-0851
CY  - Washington, DC
PB  - Soc.
M1  - PUBDB-2022-05258
SP  - 16080 - 16088
PY  - 2023
N1  - The paper is published in "ASAP" category, the volume number and page number are yet to come. The DOI number is already assigned.
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - 37523736
UR  - <Go to ISI:>//WOS:001040500800001
DO  - DOI:10.1021/acsnano.3c04835
UR  - https://bib-pubdb1.desy.de/record/483355
ER  -