Single electrons take the bus

• Published in: Nature (London) 2011-09, Vol.477 (7365), p.414-414
• Main Author: Kontos, Takis
• Format: Article
• Language: English
• Subjects: 639/766/483; Condensed Matter; Electrons; Humanities and Social Sciences; Mesoscopic Systems and Quantum Hall Effect; multidisciplinary; news-and-views; Physics; Quantum dots; Reservoirs; Science; Science (multidisciplinary)
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/477414a

Single-electron circuitry is a promising route for quantum information processing. The demonstration of single-electron transfer between two distant quantum dots brings this technology a step closer. See Letters p.435 & p.439 Electrons surfing on a sound wave Electrons strongly interact with other electrons and their environment, making it extremely difficult to isolate and detect a single moving electron in a similar way to single photons in quantum optics experiments. But now, in two unrelated reports, Hermelin et al . and McNeil et al . demonstrate that it is possible to emit a single electron from one quantum dot and detect it again with high efficiency after longevity propagation over several micrometres to another quantum dot. The single electron is isolated from other electrons as it is sent into a one-dimensional channel, where it is carried along on a surface acoustic wave induced by microwave excitation. McNeil et al . also show that the same electron can be transferred back and forth up to 60 times, a total distance of 0.25 millimetres. This work demonstrates a new way of transporting a single quantum particle over a long distance in nanostructures, and could pave the way for a range of quantum optics experiments and for quantum information circuits based on single electrons.