A novel form of computer memory that is faster and more efficient than existing components has been revealed by US scientists.
The “phase-change” memory stores binary information by switching sections of a semiconducting alloy between an ordered, crystalline phase and a disordered, amorphous phase. It has the potential to be far more efficient than existing forms of memory but has proven difficult to get working perfectly.
The new memory is made from doped germanium-antimony alloy. The researchers succeeded in making components at just 20 nanometres in diameter, which are used to store a binary bit of information. This is substantially smaller than the smallest writable section of flash memory. In addition, it was found to be between 500 and 1000 times faster than flash, while requiring about half as much power.
“You can do a lot of things with this phase-change memory that you can’t do with flash,” says Spike Narayan, senior manager of nanoscale science at IBM, who led the work.
Advertisement
Continuous power
The phase change memory is also non-volatile. The fastest and most forms of computer memory – SRAM and DRAM – must be powered continuously and repeatedly refreshed. These “volatile” forms of memory lose their stored information whenever the power supply is cut off.
“You can replace discs, do instant-on computers, or carry your own fancy computer application in your hand,” Narayan adds. “It would complement smaller technology if manufacturers wanted to conjure things up.”
The research was carried out by researchers at IBM’s Almaden Research Lab in New York, US, Japanese company Macronix and German firm Qimonda. Technical details of the research will be presented at the 2006 International Electronic Devices Meeting in San Francisco, US, in February 2007.
Ones and zeros
Most computer memory uses the presence or absence of electrical charge contained in a tiny region of material to represent individual ones and zeros of binary information.
The improved efficiency could help boost phase-change memory’s chances of replacing flash as the electronics industry continues to make devices smaller and more powerful, its makers say.
“This is a much more robust memory technology,” Narayan says. “It will be used more and more as flash gets into more and more trouble at small dimensions.”
![Astronomers have long known that understanding how star clusters come to be is key to unlocking other secrets of galactic evolution. Stars form in clusters, created when clouds of gas collapse under gravity. As more and more stars are born in a collapsing cloud, strong stellar winds, harsh ultraviolet radiation and the supernova explosions of massive stars eventually disperse the cloud, and their light can bear down on other star-forming regions in the galaxy. This process is called stellar feedback, and it means that most of the gas in a galaxy never gets used for star formation. Researching how star clusters develop can answer questions about star formation at a galactic scale. Now, the state of the art has been further developed with both Hubble and Webb working together to provide a broad-spectrum view of thousands of young star clusters. An international team of astronomers has pored over images of four nearby galaxies from the FEAST observing programme (#1783), trying to solve this mystery. Their results show that it is the most massive star clusters that clear away their gaseous shroud the fastest, and begin lighting their galaxy the earliest. The team identified nearly 9000 star clusters in the four galaxies in different evolutionary stages: young clusters just starting to emerge from their natal clouds of gas, clusters that had partially dispersed the gas (both from Webb images), and fully unobstructed clusters visible in optical light (found in Hubble images). With Webb???s ability to peer inside the gas clouds, they were able to then estimate the mass and age of each cluster from its light spectrum. This image shows a section of one of the spiral arms of Messier 51 (M51), one of the four galaxies studied in this work, as seen by Webb???s Near-Infrared Camera (NIRCam). The thick clumps of star-forming gas are shown here in red and orange, representing infrared light emitted by ionised gas, dust grains, and complex molecules such as polycyclic aromatic hydrocarbons (PAHs). Within these gas complexes, each tens or hundreds of light years across, Webb reveals the dense, extremely bright clusters of massive stars that have just recently formed. The countless stars strewn across the arm of the galaxy, many of which would be invisible to our eyes behind layers of dust, are also laid bare in infrared light. [Image description: A large, long portion of one of the spiral arms in galaxy M51. Red-orange, clumpy filaments of gas and dust that stretch in a chain from left to right comprise the arm. Shining cyan bubbles light up parts of the gas clouds from within, and gaps expose bright star clusters in these bubbles as glowing white dots. The whole image is dotted with small stars. A faint blue glow around the arm colours the otherwise dark background.]](https://images.newscientist.com/wp-content/uploads/2026/05/13114322/SEI_296271016.jpg)
