Slashdot Mirror
Magnetic Processors - Computing's New Future?
metalcoat writes "For the first time researchers have created a working prototype of a radical new chip design based on magnetism instead of electrical transistors. As transistor-based microchips hit the limits of Moore's Law, a group of electrical engineers at the University of Notre Dame has fabricated a chip that uses nanoscale magnetic "islands" to juggle the ones and zeroes of binary code.
Wolfgang Perod and his colleagues turned to the process of magnetic patterning (.pdf) to produce a new chip that uses arrays of separate magnetic domains. Each island maintains its own magnetic field. Because the chip has no wires, its device density and processing power may eventually be much higher than transistor-based devices. And it won't be nearly as power-hungry, which will translate to less heat emission and a cooler future for portable hardware like laptops."
"For the first time researchers have created a working prototype of a radical new chip design.."
Hmm. Maybe.
But this seems a lot like bubble memory to me.
And while the wiki entry doesn't mention using this for direct computation, it is indeed possible.
Coriolis effect is basically negligible across the 12 inches or whatever the major diameter a toilet bowl is. The shape of the bowl and the angle water flows into and out of it at are going to have a greater effect on the direction of flow than Coriolis effect. I wouldn't be surprised if mythbusters has tried this one.
When I first heard this claim, I watched the water drain out of the sink that night when washing dishes. I was a little disturbed when it swirled down the drain clockwise.
True, an ideal CMOS doesn't have any leakage; these days, however, the very small feature sizes translate into more and more leakage, mainly because of the tunneling effect. It's not uncommon for the leakage power to be one fifth of the entire power consumption; unfortunately, with future generations, this will only get worse.
The Raven
Yes and no. Yes, it's true that Moore's Law is not a "law" as such, but when people speak of "hitting the limit of Moore's Law" or "the end of Moore's Law" they are almost always referring to a physical limitatation to the trend of increasing transistor density and switching speeds. It's easier to say "the limit of Moore's Law" than "the regime where transistor density cannot be increased appreciably without a radical change in current semiconductor processing technology."
Wikipedia entry for Magnetic Bubble memory. I worked on Magnetic Bubble memory at IBM san jose, and the wired article sounds like this is the nano-scale version of this with some big improvements in how they are manipualted. Back then the "bubbles" were a few microns in size. You patterns permaloy onto the surface of a magnetic material. Usually this was a long loop of almost touching chevrons or T-shaped permaloy elements. the bulk materila was polarized one direction (normal to the chip) and inversions in this formed round "bubbles" for reasons simmilar to surface tension these bubbles were stable in one size and liked to stick to the chevron. Under a polarized light microscope you could see the "bubbles" in contrast sticking to the chevrons, giving them their name due to their appearance. one bubble stuck to one chevron. and the presence or absense of a bubble on a chevron was a 1 or 0. in some fancy schema the bubbles could hold internal higher order domain structures to encode more than one bit per bubble but these were never made practical.
A rotating magnetic field transverse to the chip would cause the chevrons to act like little iron bar bagnets pulling the bubble from one side to the other. because the chevron shape is asymetric it acted like a rachet and would only move the bubble unidirectionally. If the field was strong enough the bubble would then "leap" to the next chevron. Under the microscope you saw marching "bits" moving along. so you could move all the bit patterns like a train along the tracks in a bulk matterial with one layer of passive patterning. at one point in the loop track you placed a reader and a writer. this way you had sequential access to any bit and could inject or delete bits in the train.
When the power went off the bubbles stayed put.
It never made it to market (fuji made some) because it's niche was too small. it was slower than ram but faster than a hard drive. it was cheaper than ram but more expensive than a hard drive. At the time it was denser than ram but less dense than a harddrive. Thus it's only use was as a cache between ram and harddrives and in applications where robustness and non-voltility would be valuable like high-radiation sattelites and point of sale terminals. The latter market was eaten by EAROM and then flash memory.
this new material sounds like it uses simmilar concepts but is much smaller and actually performs bubble logic. Not sure about where the clock comes from: perhaps it's still a rotatin mag fiield?
Some drink at the fountain of knowledge. Others just gargle.
Specifically they are developing to the International Technological Roadmap for Semiconductors (ITRS), which is produced by the Semiconductor Industry Association (SIA), of which Intel, AMD, IBM, etc are members. This is the little-known [by the public] pre-competitive stage of the semi-conductor industry in which they all get together and collaborate on developing a "best available industrial consensus" on the way that the industry should move forward (choice of semiconductor technologies, etc).
This lecture by Sir Maurice Wilkes http://www.cl.cam.ac.uk/~mvw1/Progress_in_Compute
Magnetic bubbles move. Its principle resembles that of delay line memory used in computers before the invention of core and disk memory: You have huge circulating loops one can access at choosen spots to read a record. (People are working on optical delay line memory to store petabytes and picosecond speeds.)
I interpret this new magnetic technology to be a more compact implementation of programmable logic arrays . PLAs are standard tool in digital circuit design and can theoretically emulate any other digital state machine such as a CPU. Engineers like them because they are like blank circuits you can quickly burn a pattern in them. New high-density PLA chips in the 1980s lead to the rise of the mini-supercomputer industry, with companies like Convex using them. However, general purpose CPUs from Intel and Sun eventually exceeded 1990s PLA speeds and circuit capacities.
It seems as though you are picturing actual magnets and wires in this processor. With QCA you are working down to the level of single electrons. The natural force between electrons that pushes them apart is the magnetic force that QCA uses: essentially each little bit could be though of as a square of 2x2, with 2 electrons in opposite corners, say top-right and bottom-left. If you force an electron next to the top-right of the square, the two electrons IN the square will shift around to be in the top-left and bottom-right corners. In this way you can transmit a signal of a 0 or 1. This can be done in a VERY small space, obviously, compared to today's fabrication processes.
I have about 128 bits of it sitting in my closet somewhere. It is not based on a power of two like ram is now, but the length X width of the number of magnets on each side.
A close-up picture of it
just like all toilets swirl the other direction down under
They don't. It's a myth. The Coriolis force is too weak to enforce the direction of swirl. It depends on the toilet.
"Long run is a misleading guide to current affairs. In the long run we are all dead." (John Maynard Keynes)
To 'shield from magnetic fields' is generally the same thing as 'generate an
opposing magnetic field'; that means the shield materials ARE affected,
and are in fact somewhat magnetized, to create the shielding
effect.
The best shield materials are superconductors (which only exist at low
temperatures). The most common magnetic shield materials are soft
iron alloys (Permalloy and Mu-Metal are brand names). Shielding
from rapidly-changing magnetism is easier, most electrical conductors
will do this (but superconductors do it for constant magnetic fields
as well as changing ones). A weak shielding effect is called diamagnetism,
and is interesting in its own right. Did you know that water is repelled
from a magnetic field? Water is diamagnetic (weakly). Brass is more highly
diamagnetic.