New kind of magnetism discovered: ’Quantum Spin Liquid’
2012-12-24 0:00

From: ScienceDaily.com

Following up on earlier theoretical predictions, MIT researchers have now demonstrated experimentally the existence of a fundamentally new kind of magnetic behavior, adding to the two previously known states of magnetism.

Ferromagnetism -- the simple magnetism of a bar magnet or compass needle -- has been known for centuries. In a second type of magnetism, antiferromagnetism, the magnetic fields of the ions within a metal or alloy cancel each other out. In both cases, the materials become magnetic only when cooled below a certain critical temperature. The prediction and discovery of antiferromagnetism -- the basis for the read heads in today’s computer hard disks -- won Nobel Prizes in physics for Louis Neel in 1970 and for MIT professor emeritus Clifford Shull in 1994.

"We’re showing that there is a third fundamental state for magnetism," says MIT professor of physics Young Lee. The experimental work showing the existence of this new state, called a quantum spin liquid (QSL), is reported this week in the journal Nature, with Lee as the senior author and Tianheng Han, who earned his PhD in physics at MIT earlier this year, as lead author.


MIT physicists grew this pure crystal of herbertsmithite in their laboratory. This sample, which took 10 months to grow, is 7 mm long (just over a quarter-inch) and weighs 0.2 grams.

The QSL is a solid crystal, but its magnetic state is described as liquid: Unlike the other two kinds of magnetism, the magnetic orientations of the individual particles within it fluctuate constantly, resembling the constant motion of molecules within a true liquid.

Finding the evidence

There is no static order to the magnetic orientations, known as magnetic moments, within the material, Lee explains. "But there is a strong interaction between them, and due to quantum effects, they don’t lock in place," he says.

Although it is extremely difficult to measure, or prove the existence, of this exotic state, Lee says, "this is one of the strongest experimental data sets out there that [does] this. What used to just be in theorists’ models is a real physical system."

Philip Anderson, a leading theorist, first proposed the concept in 1987, saying that this state could be relevant to high-temperature superconductors, Lee says. "Ever since then, physicists have wanted to make such a state," he adds. "It’s only in the past few years that we’ve made progress."

The material itself is a crystal of a mineral called herbertsmithite. Lee and his colleagues first succeeded in making a large, pure crystal of this material last year -- a process that took 10 months -- and have since been studying its properties in detail.

"This was a multidisciplinary collaboration, with physicists and chemists," Lee explains. "You need both … to synthesize the material and study it with advanced physics techniques. Theorists were also crucial to this."

Through its experiments, the team made a significant discovery, Lee says: They found a state with fractionalized excitations, which had been predicted by some theorists but was a highly controversial idea. While most matter has discrete quantum states whose changes are expressed as whole numbers, this QSL material exhibits fractional quantum states. In fact, the researchers found that these excited states, called spinons, form a continuum. This observation, they say in their Nature paper, is "a remarkable first."


[...]

Read the full article at: sciencedaily.com











Related Articles
Cooking With a Magnetic Field?
Earth’s Magnetic Field Made Quick Flip- Flop
Magnets kill cancer cells in lab
Scientist Finds Hidden Portals in Earth’s Magnetic Field
Moon Oddly Magnetic—Giant Asteroid Crash to Blame?
Quantum Entanglement Leaps Beyond Einstein --"New States of Light"
Birds use quantum theory to literally ’see’ Earth’s magnetic field as they fly
For newly discovered ’quantum spin liquid’, the beauty is in its simplicity
Scientists produce a crystal that could help unlock the mystery of high-temperature superconductors


Latest News from our Front Page

Better Identification of Viking Corpses Reveals: Half of the Warriors Were Female
2015-04-25 4:52
Shieldmaidens are not a myth! A recent archaeological discovery has shattered the stereotype of exclusively male Viking warriors sailing out to war while their long-suffering wives wait at home with baby Vikings. (We knew it! We always knew it.) Plus, some other findings are challenging that whole “rape and pillage” thing, too. Researchers at the University of Western Australia decided ...
Off Your Knees, Germany! Ernst Zundel 1983 - 2003
2015-04-25 1:15
For more information on the holocaust, how the war was forced upon Germany, and the REAL victims of the second world war see: http://gblt.webs.com/Real_Holocaust.htm http://web.archive.org/web/20130806074314/http://www.666blacksun.org/ http://www.zundelsite.org/
IRS Drops Attack For Six Years – No Evidence of Jurisdiction
2015-04-24 20:29
A big congrats to a friend I’ve been working with for several years, he stood up to the predators commonly called the “IRS” and they dropped their attack. Thanks also for providing me with the proof below. The criminals called the “IRS” initiated an attack claiming my friend was required to file six tax returns, or explain how he made ...
Into Eternity - Finland's 100,000 Year Massive Underground Spent Nuclear Fuel Program
2015-04-24 20:49
Into Eternity is a documentary about a deep geological repository for nuclear waste. The concept of long-term underground storage for radioactive waste has been explored since the 1950s. The inner part of the Russian doll-like storage canisters is to be composed of copper. Hence in the case of Onkalo it is tightly linked to experiments on copper corrosion in running ...
SPLC Accuses Oath Keepers of Inciting “Armed Confrontation” Over Sugar Pine Mine
2015-04-24 20:22
The Southern Poverty Law Center has accused Oath Keepers of inciting an armed confrontation with BLM authorities over the Sugar Pine Mine dispute in Oregon, despite the fact that the organization has explicitly stated that it is not promoting armed confrontation with the feds. In an article provocatively posted on the organization’s ‘Hatewatch’ section entitled Oath Keepers Descend Upon Oregon with ...
More News »