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Quantum Mirage Images
Quantum 'mirage' may really boost nanocircuits
San Jose, Calif. (February 2, 2000) -- Some 5,000 times smaller than a human hair, this elliptical ring of 36 cobalt atoms creates a "quantum mirage" that may lead to an efficient way of moving information within future atom-scale circuits and computers, say its IBM Research inventors. When a single cobalt atom (purple peak) is placed at one of the two focus points of the elliptical ring, some of its properties suddenly appear at the other focus (the purple spot in the lower left), where no atom exists. The size and shape of the ellipse determines where information moves within the ring. The scientists at IBM's Almaden Research Center in San Jose, Calif., used a scanning tunelling microscope to position the atoms. This news was announced in the cover article of the February 3, 2000, issue of Nature, a prestigious scientific journal.
Because the quantum mirage uses the wave nature of electrons to move the information, instead of a wire -- it has the potential to enable data transfer within future nanoscale electronic circuits so small that conventional wires do not work. Many barriers must be overcome to make this scientific discovery useful in this way. But if it can be developed, the quantum mirage could enable the miniaturization of electronic circuits far beyond that envisioned today.
Quantum Mirage in Action
This four-part composite image shows the "quantum mirage" effect in action. When a magnetic cobalt atom is placed at a focus point of an elliptical corral (upper left), some of its properties also appear at the other focus (lower left), where no atoms exists. In this case, a change in the surface electrons due to the cobalt's mangetism -- the Kondo resonance -- appears as a bright spot at each focus.
When the cobalt atom is placed elsewhere within the ellipse but not at a focus point (upper right), the mirage disappears (lower right), and the Kondo effect is detected only at the cobalt atom itself.
This projection of information from an atom to another place where there is no atom was named the "quantum mirage" effect by the three IBM Almaden Research Center (San Jose, Calif.) physicists who discovered it: Hari Manoharan, Christopher Lutz and Donald Eigler.
Because the quantum mirage effect projects information using the wave nature of electrons rather than a wire, it has the potential to enable data transfer within future nanoscale electronic circuits so small that conventional wires do not work. Many barriers must be overcome to make this scientific discovery useful in this way. But if it can be developed, the quantum mirage could enable the miniaturization of electronic circuits far beyond that envisioned today.
In this case, the corral is made of 36 cobalt atoms positioned on a copper [111] surface. The discovery was first described in the cover article of the February 3, 2000, issue of Nature, a prestigious technical journal.
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