Vibration rocks for entangled diamonds

Dec 16, 2011 by Pete Wilton
double diamond illustration

(PhysOrg.com) -- Diamonds are celebrated for their enduring beauty and hardness but they can also be a physicist’s best friend.

In Nature Photonics and Science an international team of scientists report that a strange quantum state called ‘’ has been achieved in two 3mm-wide diamond crystals, spaced 15cm apart, at room temperature.

‘One of the weird effects well known from atomic-scale systems is the possibility of - the ability of an object to be in two places at once,’ explains Ian Walmsley of Oxford University’s Department of Physics, a member of the team behind the research.

‘We show that you can take two - not quite everyday objects, but at least simple and recognizable - and put them in such a state: in particular a superposition of a state of one diamond vibrating and the other not, and vice versa.

‘This special type of superposition is called "entangled" and is of a kind that may be used for applications of quantum physics to new technologies, especially in communications and computing.’

Because it is so easily disturbed by its surroundings entanglement can only normally be observed in isolated systems cooled to temperatures close to absolute zero.

But the structure of diamond makes it different: ‘Exciting a vibrational motion in diamond requires a temperature of about 2000 degrees Celsius,’ comments Joshua Nunn of Oxford University’s Department of Physics, also a member of the research team.

Laser equipment used for the experiment. Inset: one of the diamond samples used.

‘So at room temperature the vibrations are non-existent. The system behaves in that sense like a very cold cloud of atoms.’

The researchers, from Oxford University, National University of Singapore, and National Research Council of Canada, also sought to exploit another property of diamond: it tends to scatter light in such a way that a photon striking it can be converted to a lower energy photon, with the remaining energy being converted into a vibration.

This vibration or ‘ringing’ in the diamond crystal can be detected using a laser.

‘We sent bursts of laser light through both diamonds,’ Ian tells me. ‘Most of the time the light would travel straight through the crystals but sometimes the light would dump some energy in one of the crystals, setting it ringing, and the light would then emerge with less energy - a lower frequency.’

The light is combined after the crystals so that when a low frequency pulse is detected, it is possible for scientists to know that one diamond is vibrating, but not which one.

‘In fact, the universe doesn't know which diamond is vibrating!’ Joshua explains. ‘The diamonds are entangled, with one vibration shared between them, even though they are separated in space. We could use a similar technique to measure the diamonds and determine that this was the case.’

The fact that entanglement is occurring inside everyday objects is not a surprise, but up until now most people would have thought that it would be impossible to observe: being ‘washed out’ or otherwise disturbed by noise from the environment.

Joshua suggests that their approach might encourage scientists to look for strange quantum effects in places where previously they wouldn’t have expected to be able to spot them.

Whilst any practical applications for the work are a long way off, the paper does describe how it might be possible to build a diamond ‘quantum memory’ for photonic quantum computing.

Ian comments: ‘Several groups around the world have built different elements of a nanophotonic processor, and a vibrational quantum memory for photons could be incorporated into these.’

Another possibility is explored in a related piece of work using these diamonds that makes use of the character of "nothingness". It exploits this possibility to generate truly random numbers: something that could help to improve the security of electronic communications and transactions.

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Isaacsname
4 / 5 (4) Dec 16, 2011
It's funny, I'm currently watching a series on QM from a university in India, the professor explains that QM governs not just particles, but the entire universe. Quite a brilliant lecturer in my eyes. He says the part of the problem explaining QM is hindered in part by the English language :O
mattytheory
5 / 5 (3) Dec 16, 2011
Pretty sure the mathematicians and physicists that work with QM use more precise language such as mathematics. English is used to describe QM to the layperson.
axemaster
5 / 5 (3) Dec 16, 2011
Pretty sure the mathematicians and physicists that work with QM use more precise language such as mathematics. English is used to describe QM to the layperson.

You would be correct in that.
Callippo
2 / 5 (4) Dec 16, 2011
Diamonds are exceptional by strength of chemical bonds and the stability of excited states of nitrogen vacancies. It manifests with reddish fluorescence of natural diamond specimens, which lasts for seconds. The high energetic barrier of chemical bonds prohibits their spontaneous decoherence with thermal vibrations. These vacancies can be observed as glowing spots under the microscope, which is exceptional if we realize, they're represented with single atom domains.

http://www.aether...glow.jpg
http://www.aether...ancy.gif

IMO entanglement could be explained with charge coupling of excited atoms at the case of diamonds (excited electrons resonate at phase inside of both pieces).
Isaacsname
not rated yet Dec 16, 2011
Pretty sure the mathematicians and physicists that work with QM use more precise language such as mathematics. English is used to describe QM to the layperson.


I'm pretty sure since you haven't seen it you wouldn't know what I'm talking about. There's plenty of maths, it's a series of lectures for physics students.
Telekinetic
1.4 / 5 (8) Dec 16, 2011
A stringed musical instrument will resonate when a tone of one of its open strings is played across the room. Similarly, but not literally, entangled atomic structures or particles will resonate with each other in a room of another dimension, without the constriction of distance. This phenomenon will open up new insights into our multi-dimensional universe.
Callippo
1 / 5 (1) Dec 16, 2011
This phenomenon will open up new insights into our multi-dimensional universe
This is just a journalistic mumbo jumbo borrowed from thousands of popsci articles. Why it didn't opened them during last seventy years?
Telekinetic
1 / 5 (5) Dec 16, 2011
Please elaborate, Callippo, you seem hot under the collar. Multi-dimensions don't exist?
Callippo
1 / 5 (1) Dec 16, 2011
Please elaborate, Callippo, you seem hot under the collar. Multi-dimensions don't exist?
Extradimensions are considered from Kaluza times (1921), entanglement was introduced with Schrodinger (1935).

http://physics.wm...tes1.pdf
http://www.nd.edu...001.html

Why these two concepts should open our insights right now and not before fifty years or after another thirty years?
Telekinetic
1.8 / 5 (9) Dec 16, 2011
Yet many physicists still refuse to accept the multiverse. "People say the many worlds is simply too crazy, too wasteful, too mind-blowing," says Deutsch. "But this is an emotional not a scientific reaction. We have to take what nature gives us."- David Deutsch.
The reason I quote Deutsch is because his earth-shattering ideas are also put to practical use toward his instrumental work with quantum computers. He is highly respected , controversial, and bound to upset and threaten those who were educated in schools teaching dated information.
KBK
4.3 / 5 (6) Dec 17, 2011
Pretty sure the mathematicians and physicists that work with QM use more precise language such as mathematics. English is used to describe QM to the layperson.


Actually, the language and the philosophical argument came first and is still foremost. It is far more universal to the human condition than the math. The math is only as correct as the philosopher who brought the idea and potential theory to the table.

The reason the human condition is far more correct is that the human must interpret it. The philosophical argument is the foundational cornerstone to the conceptual aspects of reality, thus all vital to the human..the human...who is the only thing the argument is relevant to. Descartian logical supposition.

You may argue that the math is all important but to get there you had to pass through the philosophical mental membrane of human observational conditionals.

Math is a human tool. It's foundation is philosophy. Math has no innate capacity to leave that context.
KBK
1 / 5 (1) Dec 17, 2011
One final note:

Philosophy, in communicative and expressive language -can and does describe more than math. Inherently so. Yet math cannot leave the area of confined expression that it is within.

Humans and their philosophy can expand well beyond that area and arena.

Thus one cannot say that nothing is real, until math expresses it. Such an argument is logically invalid on all fronts.

Paradoxically and ironically...the very idea of Godel's Incompleteness theorems express this fallacy rather nicely.

Mathematics stares at itself..and finds itself wanting.
plasticpower
not rated yet Dec 17, 2011
"it might be possible to build a diamond quantum memory for photonic quantum computing"

That would be some pricey memory..
Isaacsname
2 / 5 (1) Dec 17, 2011
Thanks KBK, you illustrate that well.

For me personally, following the philosophical paths that led to the formulation of QM has been very important, that leads to an understanding of the theories, _then_ comes math, but we can't just go straight to the numbers without knowing how or why they are derived.

All science is based _first_ and foremost in philosophy.

Btw, here's the links to the series I'm watching this week, if anybody's interested..from Madras, India :)

QM, first lecture

http://www.youtub...GYe39XG0

At least he doesn't put me to sleep like Susskind, lol.
Jaeherys
3 / 5 (2) Dec 17, 2011
Maybe "back in the day" science was based on philosophy but if I was to base any argument solely on a philosophical point of view in any of my classes (biochem student) I would be laughed at. In no way is philosophy used in anything that I do when evidence can be used instead.

Philosophy is an old, almost useless method of trying to explain what goes on around us. Philosophy cannot prove anything at all other than what your brain tells you it thinks it proves. Math on the other hand has a physical basis that supersedes whatever you think may be happening philosophically.

Eventually, when our understanding of reality is great enough, there will be no need at all for philosophy as there will be math to represent it. Neuroscience is a prime example of the failure of philosophy where evidence/math makes philosophical arguments obsolete.

But hey, I'm just an undergrad and have a lot left to learn, but this is just how I see it.
Telekinetic
1.6 / 5 (7) Dec 17, 2011
[q
Eventually, when our understanding of reality is great enough, there will be no need at all for philosophy as there will be math to represent it. Neuroscience is a prime example of the failure of philosophy where evidence/math makes philosophical arguments obsolete.
But hey, I'm just an undergrad and have a lot left to learn, but this is just how I see it.
That's an interesting philosophy you've got there, kid.
AWaB
1 / 5 (1) Dec 19, 2011
KBK, you've missed the boat. QM doesn't work the way you think. It is, by its very nature, a mathematical construct. If you don't speak the language of QM, mathematics, you won't understand its concepts. There are no ifs, ands, or buts about that.
dtyarbrough
1 / 5 (1) Dec 21, 2011
The light is combined after the crystals so that when a low frequency pulse is detected, it is possible for scientists to know that one diamond is vibrating, but not which one.
In fact, the universe doesn't know which diamond is vibrating! Joshua explains. The diamonds are entangled, with one vibration shared between them, even though they are separated in space. We could use a similar technique to measure the diamonds and determine that this was the case.

Fools. Don't combine the light and you can tell which one is vibrating. What the heck does this have to do with entanglement. One of the two would have to vibrate at all times, so how would you ever detect a change if you combined the light.

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