SIN Curved LASER Beams: Orion K. June 2009

Researchers from the University of Arizona and from the University of Central Florida have made an advancement in the study of “ultra-intense” lasers. So reports Larry Greenemeier, in his article called High-Intensity Lasers Throw Scientists a Curve, published on the 10th of April 2009 at sciam.com (http://www.scientificamerican.com/article.cfm?id=high-intensity-lasers-curve). These lasers could improve scientific study by heightening researchers’ understanding of atomic, molecular, optical and plasma physics. The lasers emit brief (only 35 femtoseconds, or 3.5 x 10-14 seconds), but powerful, pulses. However, the short nature (about 10 microns, due to the brief pulses) of these pulses makes them difficult to study.

The researches bent a laser beam; an advancement that they hope will help to show them how these lasers travel though air, and also help to find new ways of using ultra-intense lasers. To make the lasers bend, the researchers “shot” the laser blasts (called bullets) at a sheet of thin glass that had a specific thickness variation. The bullets, which originally had a round shape, were turned into a more triangle-like shape. Because of their high intensity, the laser bullets ionized the air in their wake, leaving plasma behind the pulses, and giving them extreme electromagnetic energy. The bent plasma trail that is left behind can then be scrutinized by scientists. This enables them to learn much more about the structure of laser beams, which, co-author of the research Jerome Moloney says “is very important”.

A bent laser could be used to pull lightening from clouds safely, or to illuminate upper atmosphere spectroscopic studies (such as those of ozone and atmospheric CO2).

SIN Racetrack Memory: May 2009, Orion K.

A new type of solid-state memory, called racetrack memory (RM), may become the high-speed, high data density, nonvolatile, reliable, and reasonably priced option for data storage. It operates by reading and writing the electrical charge in sections of nanowire imbedded in silicone, and may achieve high data density by using three-dimensional arrays. This was reported by Stuart S. P. Parkin on page 76 of the June 2009 issue of Scientific American; his article was entitled Data in the Fast Lanes of Racetrack Memory (see for a version of the article).

RM tries to combine the benefits of the high write speeds of solid-state memory with the nonvolatile (meaning the data remains when the computer powers down) benefits of magnetic hard disk drives. Miniscule polarized electron spin sections in the RM permalloy wire (a highly magnetic nickel-iron alloy) stores data bits. This is done by assigning each section a 0 or 1 value based on the negative or positive polarized spin. Each section is separated by a “domain wall” where the spin switches from negative to positive or contrariwise. However, to read and write data, these states must pass a read/write head.

In a traditional disk drive, the read/write head moves on an arm, and the disk spins to access the data. However, RM does not need to move anything to access the data. A slight, polarized, electrical pulse could move the domain wall at 150 nanometers per nanosecond, whilst maintaining their spacing. The walls could be moved past heads that can read and write information to and from the wire.

This could reduce computers’ energy consumption and increase their lifespan by reducing moving parts and therefore reducing cooling needs.