Baby it's cold outside: a new matter to consider

[Guest guest]

In new state of matter, echoes of an old symbol

 

March 16, 2006

Courtesy University of Chicago

and World Science staff

 

Physicists say they have converted three atoms into a new state of

matter whose existence a Russian scientist predicted in 1970.

 

In this state, any two of the atoms repel each other when close

together, " but when you put three of them together, it turns out that

they attract and form a new state, " said the University of Chicago's

Cheng Chin.

 

In the laboratory of Rudolf Grimm at the University of Innsbruck in

Austria, they reported, they observed the state in a vacuum chamber

at a frigid minus 459.6 degrees Fahrenheit.

 

That's equivalent to a billionth of a degree above " absolute zero, "

the coldest temperature that can exist.

 

The new state behaves like a Borromean ring, a symbol of three

interlocking circles significant in Medieval Italy, the researchers

explained. The Borromean concept is also important in some other

aspects of physics, chemistry and mathematics.

 

" This ring means that three objects are entangled. If you pick up any

one of them, the other two will follow. However, if you cut one of

them off, the other two will fall apart, " Chin said. " There is

something magic about this number of three. "

 

The new state is called an Efimov state after the Russian researcher,

Vitaly Efimov. Chin and 10 other scientists described the finding in

the March 16 issue of the research journal Nature.

 

The physicists said they coaxed three atoms of cesium, a soft metal

used in atomic clocks, into the Efimov state. But in theory the state

is possible for any sets of three particles at ultracold

temperatures, according to Chin. " If you can create this kind of

state out of any other type of particle, it'll have exactly the same

behavior, " he said.

 

" After working on cesium for many years, this is a dream come true

for me, " he added.

 

The finding may spur new research programs devoted to understanding

the quantum mechanical behavior of just a few interacting particles,

Grimm said.

 

Quantum mechanics, the study of physical laws governing the smallest

things, is well worked out when it comes to explaining the

interactions of either two particles, or many, Chin said. But a good

understanding of systems containing a handful of particles is

elusive. That may change as scientists start to produce experiments

that simulate systems of three or four particles, like those found in

atomic nuclei.

 

Now that the Efimov state has been achieved, scientists can aspire to

engineer the properties of matter, Chin said.

 

Using so-called nanotechnology, scientists can already combine atoms

in different ways to form materials with interesting new properties,

but that doesn't change " the fundamental interactions of these

atoms, " Chin said.

 

The new findings, he added, expand those horizons. He said the

researchers exerted total control over the atoms in the experiments,

converting them into the Efimov state and back at will.

 

" This so-called quantum control over the fundamental properties of

matter now seems feasible. We're not limited to the properties of,

say, aluminum, or the properties of the copper of these particles. We

are really creating a new state in which we can control their

properties. " But not too easily: for now, he added, it seems this can

only be done at temperatures near absolute zero.

 

The Borromean rings were added to the coat of arms of the Borromeo

family, Milanese aristocrats, in the 15th century. Although there are

different accounts of what the rings stood for, one story has it that

they represented marriages that had inseparably bound the family with

two others.

 

Borromean rings. The symbol of the medieval Borromeo family, these

rings were so intertwined that removing any one caused the entire

structure to fall apart. Physicists use the term to describe some

atomic nuclei, because if any one constituent is removed, the rest of

the nucleus disintegrates. In a new state of matter, atoms themselves

form into structures of this nature.

 

 

a posting by......... bob

P.S. note to Silver: the masked man asks:how many now big

fella? LOL