Quantum entanglement stronger than suspected

New Scientist ^ | July 17, 2002 | Ian Sample

[gcruse]

Pairs of photons linked by the weird quantum effect of entanglement can pass through sheets of metal without the entanglement being destroyed. The finding means the quantum linking of particles is far more robust than scientists thought and could help them develop new ways of making quantum computers.

Scientists think quantum computers could be hugely powerful because of their ability to perform many calculations at once, instead of doing one after another like regular computers.

When photons are entangled, the physical properties of one are intimately linked to the other. Measuring the properties of one will instantly tell you the properties of the other. But many scientists believed entanglement broke down if the photons ever interacted with anything.

Now, Erwin Altewischer and his team at Leiden University in the Netherlands have shown this is not true. They used a crystal to split photons into pairs of lower energy photons with different and entangled polarisations. They then fired these entangled photons at gold sheets thick enough to block light.

Surface waves

The sheets were peppered with holes 200 nanometres wide. Although the holes were too small for light to squeeze through, Altewischer found the photons created waves of electrons on the gold surface called plasmons that passed through the holes and re-emitted the photons on the other side. Measurements showed that the emitted photons were still entangled.

"It's a good omen, because it's saying quantum entanglement can survive when you might not expect it to," says Bill Barnes, a photonics expert at the University of Exeter. "If they can survive this, what else can they survive?"

Altewischer says the fact that the entanglement is preserved, even when the light is converted into electron waves, means it could be used to develop new types of quantum computer or quantum cryptography systems.

[RightWhale]

That is indeed an alternative way to state the problem. I don't know at this time which approach yields the quicker solution or the simpler formulation.

[Duke Nukum]

...except that it's not real.

Define "real." And then test it under controlled experimental conditions.

Phil Dick said reality is that which, when you try to ignore it, doesn't go away.

That would make belief in ESP real, as the scientific community continues to ignore it, yet it persists.

[yendu bwam]

I am linking the idea that some of these extra dimensions in the string theory might be large enough to be measured in the lab, large enough to be bigger than groups of neurons in the brain, and the idea that there can be only one photon. There can be only one. Highlander.

Good one. Really good one.

[yendu bwam]

I hope those entangled photons use birth control - or we'll have a whole entangled photon family on the verge of collapse.

[gcruse]

 a whole entangled photon family

Didn't George Washington warn us against something like that?

[RightWhale]

Yeah, he was concerned with foreign entangled photons. A valid point in the existing model, but if the unified single photon model works out, foreign entangled photons wouldn't be necessary since we can entangle our own photons to our own satisfaction.

[yendu bwam]

a whole entangled photon family Didn't George Washington warn us against something like that?

Oh, yeah, 'foreign entanglements!' Took me a while, but I got it.

[yendu bwam]

we can entangle our own photons to our own satisfaction.

Thanks, but I'm not that kind of guy.

[crystalk]

In...this world...that we...know now...

Life...is here...then gone...

But some..where in the aft..erglow...

Love ...lives on, and on!

[yendu bwam]

It's a good omen, because it's saying quantum entanglement can survive when you might not expect it to

Honey, turn off the lights for a sec. The photons are entangled again...

[G Larry]

This is not news!
Gene Rodenberry had photon torpedos figured out 35 years ago!
Of course photon can pass through metal unscathed!
And force fields too!

[gcruse]

The Naked Singularity.

How did my photons become so entangled,
My WIMPs and my leptons by all this new fangled
Gauge theory?  I'm lost in quantum confusion
And chromodynamic quarks ain't the conclusion.

[yendu bwam]

I'm lost in quantum confusion

With any probability, the situation will resolve...

[gcruse]

Thank you. All I know is that I am a standard deviate.

[jwh_Denver]

Phil Dick said reality is that which, when you try to ignore it, doesn't go away

I think ESP is real. But I think it's origins will never be understood by scientists. So a lot of BS theories on it will crop up like weeds.

[yendu bwam]

My WIMPs and my leptons

The French and the Democrats?

[yendu bwam]

Thank you. All I know is that I am a standard deviate.

Better than being a complex square root.

[yendu bwam]

The Naked Singularity.

A completely warped streaker.

[Ahban]

Good post. I will call Physicist in here so that he can set me straight (unlike the other thread we are on).

I am thinking FASTER THAN LIGHT COMMUNICATION will soon be possible. Combine the newfound ability to "Freeze" light with this and you have FTL communication.

Here's how... Let's say two entangled photons are "frozen", they still keep their entangled properties, even if they don't move, am I wrong about that or do we not know yet? One photon is taken on a spaceship to alpha centauri. By manipulating the photon on earth, the one on the spaceship reacts. One type of reaction could be a DOT, the other a DASH. Presto, morse code, or even bits and bytes.

Go ahead an dash my dreams on this physie, just as I may have done to you on the "WE WILL FIND ET" thread.

[gcruse]

. But I think it's origins will never be understood by scientists.

"That is about as likely as man ever knowing what
constitutes the stars.  In other words, it is impossible."
               ---some guy or other a hundred years ago.