By a News Reporter-Staff News Editor at Science Letter -- Data detailed on Nanotechnology have been presented. According to news reporting originating from Beer Sheva, Israel, by NewsRx correspondents, research stated, "A quantum point contact (QPC) is a basic nanometre-scale electronic device: a short and narrow transport channel between two electron reservoirs. In clean channels, electron transport is ballistic and the conductance is then quantized as a function of channel width(1,2) with plateaux at integer multiples of 2e(2)/h (where e is the electron charge and h is Planck's constant)."
Our news editors obtained a quote from the research from the Ben-Gurion University of the Negev, "This can be understood in a picture where the electron states are propagating waves, without the need to account for electron-electron interactions. Quantized conductance could thus be the signature of ultimate control over nanoscale electron transport. However, even studies with the cleanest QPCs generically show significant anomalies in the quantized conductance traces, and there is consensus that these result from electron many-body effects(3,4). Despite extensive experimental and theoretical studies(4-11), understanding these anomalies is an open problem. Here we report that the many-body effects have their origin in one or more spontaneously localized states that emerge from Friedel oscillations in the electron charge density within the QPC channel. These localized states will have electron spins associated with them, and the Kondo effect-related to electron transport through such localized electron spins-contributes to the formation of the many-body state(5-7). We present evidence for such localization, with Kondo effects of odd or even character, directly reflecting the parity of the number of localized states; the evidence is obtained from experiments with length-tunable QPCs that show a periodic modulation of the many-body properties with Kondo signatures that alternate between odd and even Kondo effects. Our results are of importance for assessing the role of QPCs in more complex hybrid devices(12,13) and for proposals for spintronic and quantum information applications(14,15)."
According to the news editors, the research concluded: "In addition, our results show that tunable QPCs offer a versatile platform for investigating many-body effects in nanoscale systems, with the ability to probe such physics at the level of a single site."
For more information on this research see: Odd and even Kondo effects from emergent localization in quantum point contacts. Nature, 2013;501(7465):79-83,111. Nature can be contacted at: Nature Publishing Group, Macmillan Building, 4 Crinan St, London N1 9XW, England. (Nature Publishing Group - www.nature.com/; Nature - www.nature.com/nature/)
The news editors report that additional information may be obtained by contacting M.J. Iqbal, Ben Gurion University of the Negev, Ilse Katz Inst Nanoscale Sci & Technol, IL-84105 Beer Sheva, Israel. Additional authors for this research include R. Levy, E.J. Koop, J.B. Dekker, J.P. de Jong, J.H.M. van der Velde, D. Reuter, A.D. Wieck, R. Aguado, Y. Meir and C.H. van der Wal (see also technology.html">Nanotechnology).
Keywords for this news article include: Asia, Israel, Nanoscale, Beer Sheva, Nanotechnology, Emerging Technologies
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