Chameleon magnets: ability to switch magnets 'on' or 'off' could revolutionize computing

May 27, 2011
Theoretical physicist Igor Zutic has been exploring ways to use magnets to revolutionize computing. A new article in Science may show that it is possible.

(PhysOrg.com) -- What causes a magnet to be a magnet, and how can we control a magnet's behavior? These are the questions that University at Buffalo researcher Igor Zutic, a theoretical physicist, has been exploring over many years.

He is one of many scientists who believe that magnets could revolutionize computing, forming the basis of high-capacity and low-energy memory, and data transfer devices.

Today, in a commentary in Science, Zutic and fellow UB physicist John Cerne, who studies magnetism experimentally, discuss an exciting advancement: A study by Japanese scientists showing that it is possible to turn a material's magnetism on and off.

A material's magnetism is determined by a property all possess: something called "spin." Electrons can have an "up" or "down" spin, and a material is when most of its electrons possess the same spin. Individual spins are akin to tiny bar magnets, which have north and south poles.

In the Japanese study, which also appears in the current issue of Science, a team led by researchers at Tohoku University added cobalt to , a nonmagnetic semiconductor, to create a new material that, like a chameleon, can transform from a paramagnet (a nonmagnetic material) to a (a ) at room temperature.

To achieve change, the researchers applied an to the material, exposing the material to extra electrons. As Zutic and Cerne explain in their commentary, these additional electrons -- called "carriers" -- are mobile and convey information between fixed cobalt ions that causes the spins of the cobalt electrons to align in one direction.

In an interview, Zutic calls the ability to switch a magnet "on" or "off" revolutionary. He explains the promise of magnet- or spin-based computing technology -- called "spintronics" -- by contrasting it with conventional electronics.

Modern, record and read data as a blueprint of ones and zeros that are represented, in circuits, by the presence or absence of electrons. Processing information requires moving electrons, which consumes energy and produces heat.

Spintronic gadgets, in contrast, store and process data by exploiting electrons' "up" and "down" spins, which can stand for the ones and zeros devices read. Future energy-saving improvements in data processing could include devices that process information by "flipping" spin instead of shuttling electrons around.

In their Science commentary, Zutic and Cerne write that chameleon magnets could "help us make more versatile transistors and bring us closer to the seamless integration of memory and logic by providing smart hardware that can be dynamically reprogrammed for optimal performance of a specific task."

"Large applied magnetic fields can enforce the spin alignment in semiconductor transistors," they write. "With chameleon magnets, such alignment would be tunable and would require no magnetic field and could revolutionize the role ferromagnets play in technology."

In an interview, Zutic says that applying an electric voltage to a semiconductor injected with cobalt or other magnetic impurities may be just one way of creating a chameleon magnet.

Applying heat or light to such a material could have a similar effect, freeing electrons that can then convey information about spin alignment between ions, he says.

The so-far elusive heat-based chameleon magnets were first proposed by Zutic in 2002. With his colleagues, Andre Petukhov of the South Dakota School of Mines and Technology, and Steven Erwin of the Naval Research Laboratory, he elucidated the behavior of such magnets in a 2007 paper.

The concept of nonmagnetic materials becoming magnetic as they heat up is counterintuitive, Zutic says. Scientists had long assumed that orderly, magnetic materials would lose their neat, spin alignments when heated -- just as orderly, crystalline ice melts into disorderly water as temperatures rise.

The carrier electrons, however, are the key. Because heating a material introduces additional carriers that can cause nearby electrons to adopt aligned spins, heating chameleon materials -- up to a certain temperature -- should actually cause them to become magnetic, Zutic explains.

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User comments : 17

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gunslingor1
1.7 / 5 (7) May 27, 2011
Sounds like an electromagnet made of an alloy to me. Are you saying magnitism is maintained after the current is removed? Still sounds like an alloy electromagnet to me.
Na_Reth
5 / 5 (1) May 27, 2011
This is basicly about controlling the spin of the electrons.
Garfieldo
2.3 / 5 (6) May 27, 2011
yet another "paper" in science written by a guy who explains what's in another paper of the same issue.... easy way to expand one's h-factor by taking partial credits for what has been done.. And it's working !!! it's actually this guy's picture that appears here, and not the pics from the japanese team who actually carried the original work out !!
Please PhysOrg, correct this and first cite the original work.
Just My humble opinion.
that_guy
5 / 5 (6) May 27, 2011
Sounds like an electromagnet made of an alloy to me. Are you saying magnitism is maintained after the current is removed? Still sounds like an alloy electromagnet to me.


It is not an electromagnet in the traditional sense. It works similar to a transistor. You add electrons, and it becomes magnetic. It doesn't explain the drain mechanism, but it sounds like you would apply a positive voltage to drain them, and it will no longer be magnetic.

The reason why it isn't like an electromagnet is that it doesn't need a constant current to create a magnetic field.
KingDWS
not rated yet May 27, 2011
The reason why it isn't like an electromagnet is that it doesn't need a constant current to create a magnetic field.

Just sounds like they re-invented 70's era magnetic bubble memory and now are giving it a new twist.
sender
not rated yet May 28, 2011
Could utilizing non-blinking quantum dots to optically modulate such a mechanism yield waveguide compression and spatial light modulation at a faster frequency for data storage, recovery and/or relay?
Zak_Mc_Kee
not rated yet May 28, 2011
i would bet it has something to do with marko rodin's coil design, and the true way electrons want to flow.
that_guy
5 / 5 (3) May 28, 2011
Could utilizing non-blinking quantum dots to optically modulate such a mechanism yield waveguide compression and spatial light modulation at a faster frequency for data storage, recovery and/or relay?

The only thing this comment has to do with the article in discussion is 'data storage'
ppnlppnl
5 / 5 (3) May 29, 2011

What I'm about to say will seem like nonsense...

Yeah, You really didn't say anything that rises to the level of nonsense.

Hey, I read the whole thing so I'm allowed to flame. Right?
Tachyon8491
1 / 5 (2) May 30, 2011
What is conspicuously missing in this article are the relevant switching parameters which would show this technology to offer superior performance - what operational voltages cause 1/0 switching; what is the typical hysteresis curve per switching element here; can this technology e.g. switch as fast as SOS (silicon on Saffire which is already twenty years old?); what is the maximum operational frequency; explanation of remanence effects here? ; what are expected power levels per integration complexity? ; Much of this sounds like a backward step in technology unless such parameters are explicitly presented...
CSharpner
5 / 5 (3) May 30, 2011
Kev,

Now, AGAIN, for the unteenth time: If the universe is only 6000 years old, why is it that we see objects BILLIONS of light years old?

Poof! I just made Kev disappear.
CSharpner
5 / 5 (1) May 31, 2011
Kev,

Now, AGAIN, for the unteenth time: If the universe is only 6000 years old, why is it that we see objects BILLIONS of light years old?

Poof! I just made Kev disappear.

Sorry, I meant billions of light years "AWAY", not "OLD"... duh.
danman5000
not rated yet May 31, 2011
a ball of water which has a circumference of 28000 miles and is floating in space, then forcefully presurise that ball and change the elements within it to create a planet just like earth.

Where did all this water come from in the first place?

What is the source of the force to pressurize the water, and why did it act so suddenly? Do you realize how much force would be necessary to transmute water into other things? Is that possible, even in principle?

I wish you stuck around for more than your standard drive-by single comment. These are very basic concerns about your theory, which should be easily answerable by you.
whoyagonacal
5 / 5 (1) May 31, 2011
I wish you stuck around for more than your standard drive-by single comment. These are very basic concerns about your theory, which should be easily answerable by you.


Have you considered reporting @kvtrs for abuse? I think it would be fun to get him booted off the site so he can take his trolling elsewhere.
FrankHerbert
1.7 / 5 (6) Jun 02, 2011
Everyone reading this should report kevinrtrs' comment above.
Skultch
5 / 5 (2) Jun 03, 2011
The effect will be a planet that has a decaying magnetic field as observed on earth at present.


Source? The only sources I can find are on creationist websites, who's claims are easily debunked with a simple google search. Specifically, the theory suffers from obsolete understanding of the source of the magnetic field.

We don't know enough about the makeup of the Earth's core, you say? Then you can't use anything about the magnetic field to support any theory.

Also, the usage of "decaying" and "at present" makes no sense.
aroc91
not rated yet Jun 12, 2011
yet another "paper" in science written by a guy who explains what's in another paper of the same issue.... easy way to expand one's h-factor by taking partial credits for what has been done.. And it's working !!! it's actually this guy's picture that appears here, and not the pics from the japanese team who actually carried the original work out !!
Please PhysOrg, correct this and first cite the original work.
Just My humble opinion.


They're called reviews. Their purpose is to typically compare and contrast related work and simplify it to a certain extent in order to explain it better.