Saturday, August 10, 2013

Physics breakthrough in Hamburg: nano-tiny vortices new data storage - Spiegel Online

Even the hall in the basement of the University of Hamburg is crammed with technology. On a dozen screens dancing graphs, figures flicker across instruments. Plenty of space is not the four physicists in their laboratory. The mission of the research is the reduction of storage media. If their plan works, data storage could shrink greatly. But the way to lead a very large machine, which even has its own space.

“This is our ultra-high vacuum system.” The group leader Roland Wiesendanger shows on a stainless steel apparatus and emphasizes the “Ultra”. Because: “The vacuum is better than that in outer space.” It is broken, it takes longer than a week to pump the system back to some trillionth of atmospheric pressure empty. So evacuated the apparatus must nevertheless be for the research that has brought the group of scientists on the current cover of the magazine “Science”: reading and manipulating tiny magnetic structures – the so-called skyrmions

. climb over the machine

skyrmions could be a response to the many issues raised by the industry computer memory problem. Because data are left with these structures hold the storage media would smaller, have more capacity and would also be more power efficient.

A crucial step in this direction is the Hamburg physicists have succeeded: With a special scanning tunneling microscope, the researchers were able to Niklas Romming to write skyrmions in a few atomic layers thin metal layer and delete it. The research of scientists represents a start on the road to spintronic dar. The compound word describes a technique that is not in the conventional way using only the charge of electrons, but includes an additional property of tiny particles. Spinning the

“skyrmions are quasi-particles – in this case. nodes you have small two-dimensional magnetic properties of particles, but are not,” says physicist Christian Hanneken. Only about ten laboratories in the world is currently dealing with the vertebrae, which are a few nanometers in size, the researchers said. “Only in the past few years, the field is booming,” says Kirsten von Bergmann, who has also worked on the study. The interest of the industry is also increasing gradually. It has the physicist Tony Skyrme, after which the structures were named, they mathematically described already in the sixties.

 for larger view

Working Group Wiesendanger / University of Hamburg / Science

skyrmions writing process: Currents “write” on magnetic vortex crystals

Christian Hanneken expressed at the behemoth of stainless steel over, is locally covered with aluminum foil. He climbs over the system and shows arrived back on the floor, on their end. There physicists feed a sample which they then edit the vacuum spheres, similar to small clean rooms. Only after that skyrmions can read and write to the sample and measure about microscopes.

“The best time to measure is on weekends and at night,” says Niklas Romming, lead author of the study. Then disturbances are minimal. At that time barely reached shocks of running around students in the upper floors, the air-cushioned and specially protected plant, supplemented Hanneken and points it finger at the ceiling.

crystal smooth like wax of a candle

Hanneken physicist runs around the system and explains further: For the research iridium crystals after a particularly thorough cleaning and a kind of “sand blasting with ions” heated briefly. From station to station, it reaches the sample with small gripper arms on, in another part of the system. He carefully handled to only a few millimeters large crystal into a chamber and heated it until it glows brightly. “It’s like a wax candle that you have roughened with a fork outside,” he explains. “Is she gonna be hot, the wax smoothes.”

evaporate the material, the researchers on a thin layer of iron atoms and on palladium. Only now lands in the crystal scanning tunneling microscope, which not only scans it and can map on screens in the next room. The researchers also use the device for writing. “We just need to change the parameters for time and again,” says Romming. They can not watch the process therefore. Only later did she see if her writing process was successful. It takes place at temperatures a few Kelvin above absolute zero instead, and while a strong magnetic field generated by the researchers by pulling the crystal.

thus written skyrmions could continue to represent bits, ie zeros and ones, be suitable – and for data storage. “We come with today’s technology to the physical limits to one terabit per square inch,” explains Romming. Disks on skyrmions basis could the current density tenfold to hundredfold, the researchers estimated.

their research, the scientists have for the first time demonstrated that this technique at all suitable for data storage and record as many skyrmions and can also be deleted. Companies such as IBM, therefore, have their eye on the few nanometer large eddy.

yet is the work of the Hamburg physicists basic research. In order to realize stable storage, they must find, especially new materials. Where even at room temperature large magnetic fields would be integrated to save skyrmions. Currently, scientists lose the tiny vertebrae and thus the data when the magnetic collapse and the temperature in the devices increases. They can prevent only with liquid helium for cooling. In the large gray container to which physicists stand in a semicircle, would easily have been a whole chair. For normal use, the technology is far from suitable. But the cooling would rob users in everyday life the place – and it would not only in small physics laboratories pretty tight

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