Quantum chip: device handles ions as if they were data.Physicists have created a microchip that can hold an electrically charged atom and move it back and forth within a narrow channel. These manipulations lay the groundwork for using trapped ions as data bits in computer chips, the developers of the new device say.
The scientists created the chip as a step toward a new breed of computers, called quantum computers, which represent information using quantum properties of particles (SN: 7/17/04, p. 46). Those potentially mighty, yet currently rudimentary, machines are expected to efficiently handle calculations--for instance, breaking encryption codes used for Internet transactions--that would take conventional computers a billion years.
Led by Christopher R. Monroe of the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. in Ann Arbor Ann Arbor, city (1990 pop. 109,592), seat of Washtenaw co., S Mich., on the Huron River; inc. 1851. It is a research and educational center, with a large number of government and industrial research and development firms, many in high-technology fields such as , the new chip's makers also propose additional uses of their device. With further development, it might serve as a component of minuscule minuscule
Lowercase letters in calligraphy, in contrast to majuscule, or uppercase letters. Unlike majuscules, minuscules are not fully contained between two real or hypothetical lines; their stems can go above or below the line. atomic clocks (SN: 9/4/04, p. 150) or of tiny mass spectrometers, which identify substances by ionizing and measuring fragments of their molecules (SN: 6/12/04, p. 373).
The team unveils the chip, which operates in a vacuum at room temperature, in the January Nature Physics.
"This will be a great stepping-stone," comments atomic physicist Jorg Schmiedmayer of the University of Heidelberg in Germany. "Miniaturization min·i·a·tur·ize
tr.v. min·i·a·tur·ized, min·i·a·tur·iz·ing, min·i·a·tur·iz·es
To plan or make on a greatly reduced scale.
min is, in my opinion, the best way to extend ion trapping:'
Since the 1950s, physicists have machined and assembled larger containers to hold just a few ions for such purposes as studying fundamental physics and creating atomic clocks. More recently, researchers have trained lasers on eight trapped ions to tune the particles' quantum states in ways needed for computing.
Traps on chips are the way to go to create quantum computers, says Monroe. Traps will need to be smaller than the machined ones to confine ions tightly, so as to maintain their collective quantum states and to speed their interactions. Practical quantum computers will require manipulations of a few dozen to a million or so ions in close proximity, Monroe says.
On chips, the ion-trap designs could be easily repeated to handle more particles, Monroe says.
Miniaturization onto chips has already played a role in the manipulation of neutral atoms (SN: 6/17/00, p. 399). However, notes Schmiedmayer, a pioneer of the neutral-atom chip, that technology differs from what's required for handling ions.
To build the new ion device, Monroe and his colleagues used conventional microchip-fabrication methods to first deposit layers of the semiconductor compounds gallium arsenide An alloy of gallium and arsenic compound (GaAs) that is used as the base material for chips. Several times faster than silicon, it is used in high frequency applications such as cellphones, DVD players and fiber optics. and aluminum gallium arsenide onto a gallium arsenide wafer. The scientists next etched etch
v. etched, etch·ing, etch·es
a. To cut into the surface of (glass, for example) by the action of acid.
b. away portions of the wafer and the overlying overlying
suffocation of piglets by the sow. The piglets may be weak from illness or malnutrition, the sow may be clumsy or ill, the pen may be inadequate in size or poorly designed so that piglets cannot escape. layers to create a gap that's wide at the bottom of the structure, permitting laser-beam access, but only 60 micrometers across at the top.
Flanking this topmost channel are rows of electrodes Electrodes
Tiny wires in adhesive pads that are applied to the body for ECG measurement.
Mentioned in: Electrocardiography that generate electric fields to suspend ions and shuttle them along the channel.
Although the devices made so far can store and move only one cadmium cadmium (kăd`mēəm) [from cadmia, Lat. for calamine, with which cadmium is found associated], metallic chemical element; symbol Cd; at. no. 48; at. wt. 112.41; m.p. 321°C;; b.p. 765°C;; sp. gr. 8. ion at a time, the route is now open to chips containing more ions, Monroe says. With those, he adds, scientists will probably duplicate and then surpass the feats of quantum manipulation already attained with conventional ion traps.