Physics of Quantum Rings

This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

Professor Vladimir M. Fomin develops theory of strain-induced nano-architectures, in particular, physical properties of self-assembled nano- and microstructures (quantum rings, rolled-up semiconductor and superconductor membranes, superlattices of quantum dots) at the Institute for Integrative Nanosciences (IIN), Leibniz Institute for Solid State and Materials Research (IFW), Dresden, Germany (since 2009). He made his doctoral studies in Kishinev at the Department of Theoretical Physics of the State University of Moldova and received the Ph.D.degree in theoretical physics in 1978. Since then he worked in the Laboratory “Physics of Multi-Layer Structures” at the State University of Moldova. His research interests embraced non-linear optical properties and transport due to the charge-vibration interaction in semiconductors and in multi-layer structures, including derivation of the phonon spectra and the electron-phonon interaction; classification of polaritons and phonons; platonic, bipolaronic and excitonic effects in arbitrary multi-layer structures. He won a State Prize of Moldova in 1987. He received the degree of Dr. habilitat in physical and mathematical sciences from the Academy of Sciences of Moldova in 1991. He is a University Professor in Theoretical Physics (State University of Moldova, since 1995). As a Research Fellow of the Alexander von Humboldt Foundation he worked at the Martin-Luther-University of Halle-Wittenberg (1993–1994). He was associated with the Laboratory Theoretical Solid State Physics (TFVS) (University of Antwerp, 1995–2008) and with the Group Photonics and Semiconductor Nanophysics and COBRA Inter-University Research Institute (Eindhoven University of Technology, 1998–1999, 2003–2007), Division Quantum and Physical Chemistry (Catholic University of Leuven, 2008) and Faculty of Physics and Center for Nanointegration (CeNIDE) (University of Duisburg-Essen, Duisburg, 2009-2009). He received a Diploma of a Scientific Discovery of the Phenomenon of the Propagation of Spatially-Extended Interface Phonon Polaritons in Composite Superlattices from the Academy of Natural Sciences of Russia (1999). He was bestowed a medal “Academician P. L. Kapitsa” by the Academy of Natural Sciences of Russia (2000). In 2007 he was elected a Honorary Member of the Academy of Sciences of Moldova. In 2011, he edited a special issue on Modern Advancements in Experimental and Theoretical Physics of Quantum Rings of the Journal of Nanoelectronics and Optoelectronics. His present scientific directions cover diversified fields in physics of nanostructures: optical properties of quantum dots, persistent currents and magnetization of quantum rings; phase boundaries and vortex matter in meso-, nanoscopic and patterned superconductors; superconducting properties of metallic nanograins; surface-induced magnetic anisotropy in mesoscopic systems of dilute magnetic alloys; quantum transport in sub-0.1 micron semiconductor devices; vibrational excitations and polaronic effects in nanostructures; thermoelectric properties of semiconductor nanostructures. 2 monographs, 3 textbooks, 7 reviews, 10 patents, 169 scientific articles and 277 conference presentations (including 39 invited).