The New

The New, the Best, and the Worst
Collected by Pim Borman, Website Editor, SW Indiana PC Users Group, Inc.
http://swipcug.apcug.org/
swipcug@sigecom.net

Spintronics
No one, fifty years ago, could have foreseen or even imagined how the advent of evermore powerful computers would revolutionize science, technology, commerce, and communications. Vastly improved algorithms and architectural structures have been important, but the crucial factor has been the ability to cram ever smaller and more complex circuits on a semiconductor chip. That ability is now approaching a limit posed by atomic size and increasing influence of quantum effects. We may have to learn how to do more with what we already have if we want to further improve computers so that they'll be able to predict the weather or model the Big Bang, to mention just a few challenges.

From an electro-mechanical standpoint every digital computer, no matter how primitive or advanced, consists of on-off electrical switches connected in a circuit. In semiconductor-based systems the binary 0's and 1's are represented by electrons that carry a negative charge, and missing electrons, called “holes,” with positive charge. That is simple and straightforward enough. But wait, there is more...

There can be no electricity without magnetism. They are like heads and tails, yin and yang, up and down. Electrons, the elemental carriers of electricity, also are elementary magnets. You can, very much simplified, think of them as spinning spheres of electricity, tiny electromagnets in other words. Depending on the direction of spin, the magnetism points up or down. Technology making use of the magnetic properties of electrons is often referred to as “spintronics.” So far, computers ignore the magnetic state of the electrons, but what if we learned to use it for additional information storage?

About 50 years ago scientists learned how to manipulate and record the magnetic properties of electrons and certain atomic nuclei to examine the composition of substances, using a technique called nuclear magnetic resonance (NMR). Eventually that technique was extended to examine the characteristics of human tissue. The name was changed to Magnetic Resonance Imaging (MRI) to avoid the term “nuclear” with its negative connotations, although it has nothing to do with damaging radiation or nuclear energy in this case.

More recently, in the late 90's, scientists at IBM learned how to use spintronics to make very small, highly sensitive read-heads for use with computer hard drives. The sensors consist of a microscopic sliver of semiconductor sandwiched between two thin magnetic layers. The top layer is a permanent, “hard” magnet, but the bottom layer is a soft magnet that changes magnetic orientation easily as it passes over the magnetic regions on the disk. If both magnets in the head are oriented in the same direction, electrons align magnetically in the same direction and move easily through the semiconductor. If the magnetic layers point in opposite directions, the electron spin is reversed as it moves through the semiconductor, affecting its mobility and therefore the amount of current. Clever, isn't it? Practically all newer hard drives use that technology now.

If computers could be designed to use both the electrical charge and the magnetic state of electrons, each unit of information could have four different quaternary values (0,1,2,and 3) instead of the two binary values (0 and 1) currently used, resulting in greatly increased performance. But the semiconductors must be magnetic to recognize the magnetic 'up' or 'down' state of electrons. Magnetic semiconductors are few and far between, and so far none remain magnetic at room temperature.

If the material problems can be solved, we may be looking at future computers that are not only more powerful, but also easier to use. Because magnetic semiconductors retain their logic states without power, systems could be instant-on and use less power. Also, principal functions of a computer, such as logic operations, communication between circuits, and data storage, could be integrated in a single material, resulting in smaller and faster computers with high data-storage capacities and fast performance.

Making spintronic computers possible depends on chemists formulating magnetic semiconductors able to support the technology. Much progress is being made, but it will take a while longer. Not surprisingly, this article was based on an article in Chemical and Engineering News, Aug. 28, 2006.

Cookies With Gas?
Would you believe Internet via the gas meter? A San Diego-area start-up company, Nethercomm, claims to have developed technology to send broadband and TV services through the underground natural gas pipes. A converter box attached to your gas meter receives the signals and sends them to your computer or TV set. The headline of the article in USA Today (9/11/06) says it all: “Gas-line broadband a pipe dream?” (Thanks, Duane Morrow).

A Linux Epiphany
I wasn't going to mention Linux this month, but... James Derk, our local computer guru known for his syndicated weekly computer columns for Scripps-Howard News Service, has been pooh-poohing desktop Linux for years. Guess what. His column in the Evansville Press and Courier of September 18, 2006 is headed “It may be time to give Linux another try.” He specifically mentions the Ubuntu Linux distribution which, he writes, is “...painfully easy to get up and running ... without spending a dime.” Derk keeps his columns at www.cyberdads.com/blog.html You can also find them on the Scripps Howard Web site at www.shns.com/ under Columns...Business, Finance, and Technology...Compute.

Reap What You Sow!
I've been getting bored with being a one-man Linux SIG in the SW Indiana PC Users Group. I suggested to our new Region 6 Advisor of the Association of PC User Groups (APCUG), Jerry Gillette, that APCUG might be able to sponsor a way to exchange news and information between Linux aficionados scattered amongst its member Groups. He passed the word, and the suggestion was accepted with enthusiasm. APCUG now carries a new Conference (section) on its Web Board, APCUG.linux. Of course, the Conference requires a moderator, and who do you think got “volunteered?” Right, “c'est moi” said the fool. Oh well, one must reap what one sows. Access the APCUG Web Board at webboard.apcug.org and leave a message!

There is no restriction against any non-profit group using this article as long as it is kept in context with proper credit given the author. The Editorial Committee of the Association of Personal Computer User Groups (APCUG), an international organization of which this group is a member, brings this article to you.