Designing quantum dots for solotronics

• Published in: Nature communications Vol. 5; no. 1; p. 3191
• Main Authors: Kobak, J., Smoleński, T., Goryca, M., Papaj, M., Gietka, K., Bogucki, A., Koperski, M., Rousset, J.-G., Suffczyński, J., Janik, E., Nawrocki, M., Golnik, A., Kossacki, P., Pacuski, W.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.01.2014; Nature Publishing Group; Nature Pub. Group
• Subjects: 140/125; 639/301/119; 639/301/930/1032; 639/624/400/1101; 639/925/357/1017; Electrons; Humanities and Social Sciences; Molecular beam epitaxy; multidisciplinary; Quantum dots; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms4191

Solotronics, optoelectronics based on solitary dopants, is an emerging field of research and technology reaching the ultimate limit of miniaturization. It aims at exploiting quantum properties of individual ions or defects embedded in a semiconductor matrix. It has already been shown that optical control of a magnetic ion spin is feasible using the carriers confined in a quantum dot. However, a serious obstacle was the quenching of the exciton luminescence by magnetic impurities. Here we show, by photoluminescence studies on thus-far-unexplored individual CdTe dots with a single cobalt ion and CdSe dots with a single manganese ion, that even if energetically allowed, nonradiative exciton recombination through single-magnetic-ion intra-ionic transitions is negligible in such zero-dimensional structures. This opens solotronics for a wide range of as yet unconsidered systems. On the basis of results of our single-spin relaxation experiments and on the material trends, we identify optimal magnetic-ion quantum dot systems for implementation of a single-ion-based spin memory. Single-atom dopants embedded in a semiconductor matrix are of potential use for optical, spintronics as well as information storage applications. Here, Kobak et al. realize CdTe and CdSe quantum dots with single cobalt and manganese ions and show how the quantum dot design influences single-spin relaxation time.