Subatomic quantum memory in diamond demonstrated

Jun 27, 2011
This is Greg Fuchs of University of California - Santa Barbara. Credit: UCSB

Physicists working at the University of California, Santa Barbara and the University of Konstanz in Germany have developed a breakthrough in the use of diamond in quantum physics, marking an important step toward quantum computing. The results are reported in this week's online edition of Nature Physics.

The physicists were able to coax the fragile contained within a single electron in diamond to move into an adjacent single nitrogen nucleus, and then back again using on-chip wiring.

"This ability is potentially useful to create an memory element in a quantum computer based on diamond, since the subatomic nuclear states are more isolated from destructive interactions with the outside world," said David Awschalom, senior author. Awschalom is director of UCSB's Center for Spintronics & Quantum Computation, professor of physics, electrical and computer engineering, and the Peter J. Clarke director of the California NanoSystems Institute.

Awschalom said the discovery shows the high-fidelity operation of a quantum mechanical gate at the atomic level, enabling the transfer of full quantum information to and from one electron spin and a single nuclear spin at room temperature. The process is scalable, and opens the door to new solid-state quantum device development.

Scientists have recently shown that it is possible to synthesize thousands of these single electron states with beams of nitrogen atoms, intentionally creating defects to trap the single electrons. "What makes this demonstration particularly exciting is that a nitrogen atom is a part of the defect itself, meaning that these sub-atomic memory elements automatically scale with the number of logical bits in the quantum computer," said lead author Greg Fuchs, a postdoctoral fellow at UCSB.

Rather than using logical elements like transistors to manipulate digital states like "0" or "1," a quantum computer needs logical elements capable of manipulating quantum states that may be "0" and "1" at the same time. Even at ambient temperature, these defects in diamond can do exactly that, and have recently become a leading candidate to form a quantum version of a transistor.

However, there are still major challenges to building a diamond-based quantum computer. One of these is finding a method to store quantum information in a scalable way. Unlike a conventional computer, where the memory and the processor are in two different physical locations, in this case they are integrated together, bit-for-bit.

"We knew that the nitrogen nuclear spin would be a good choice for a scalable quantum memory –– it was already there," said Fuchs. "The hard part was to transfer the state quickly, before it is lost to decoherence."

Awschalom explained: "A key breakthrough was to use a unique property of –– that two quantum objects can, under special conditions, become mixed to form a new composite object." By mixing the quantum spin state of the electrons in the defect with the spin state of the nitrogen nucleus for a brief time –– less than 100 billionths of a second –– information that was originally encoded in the electrons is passed to the nucleus.

"The result is an extremely fast transfer of the quantum information to the long-lived nuclear spin, which could further enhance our capabilities to correct for errors during a quantum computation," said co-author Guido Burkard, a theoretical physicist at the University of Konstanz, who developed a model to understand the storage process.

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StandingBear
3 / 5 (4) Jun 27, 2011
Just knew the StargateSG-1 Go'auld were on to something with those crystals that form the base of their computers.
TabulaMentis
1 / 5 (2) Jun 27, 2011
Include 'Quartz Crystals' too!

Also include the crystals that some stories/rumors/movies have with 6" long crude looking crystals with rough edges plugged (pushed down) into sockets on consoles in UFOs.
Noumenon
3.9 / 5 (63) Jun 27, 2011
Didn't HAL have crystal memory modules?
robbor
5 / 5 (1) Jun 27, 2011
bet DeBeers is salivating
FroShow
3 / 5 (2) Jun 28, 2011
I was thinking of Superman's Fortress of Solitude.
In any case; I think all the new technologies being developed using diamond is going to increase the demand for higher-quality diamonds (ie, less impurities), which nature doesn't produce. So unless DeBeers gets onto the diamond manufacturing wagon train, they're going to be stuck selling a 'cheap' product to the masses. Eventually the only value in their diamonds will be that they're natural.
TheCyndicate
not rated yet Jun 28, 2011
Wait, hold on here, is this a physical memory in a particle that experiences no time at all? Isn't that a conundrum? If that's the case, then this could be used to help prove time doesn't really exist at all. A "Memory", by definition, is the recreation of past information/experiences. This would suggest that informational events are completely time independent. That has HUGE implications. :::Scratches head:::
Royale
not rated yet Jun 28, 2011
robbor, bet you're right. But if this actually pans out we could play it one of two ways. a) Our next war. b) use man-made diamonds since we wouldn't need them to be exceptionally large. (or so it seems from the article).
FroShow
1 / 5 (1) Jun 28, 2011
@TheCyndicate: The particles used to store the information are electrons, and the protons/neutrons in the nitrogen nucleus; both of which have mass and therefore experience time.

What particles out there don't experience time (other than photons)?
TheCyndicate
1 / 5 (2) Jun 28, 2011
ANY particle that moves at 'c' or greater than 'c'(Thought not possible, but quantum entanglement can be considered a loophole in this), does not experience time at all. This also has implications for the Heisenberg Uncertainty Principle. How do they know where it is, what its doing, while they know how fast it is doing it?

More data please =)
Royale
not rated yet Jun 29, 2011
Cyndicate. I don't follow. Do you have any references here to perhaps even theory? The only way I would picture light moving faster than c would be at a black hole, and maybe that's not even right, since we don't really know what happens inside. I've just never heard anything about 'one way' light and don't see how that makes a difference. Wouldn't sending a laser down a hallway and measuring it there be 'one way' light?
J-n
5 / 5 (2) Jun 29, 2011
The speed of light is constant in a vacuum not in other media. So it is possible to have light traveling faster than "other" light, depending on the media that it has to travel through.

From what i know entanglement does not allow for faster than light information transfer.

I could be wrong... but..
Noumenon
3.9 / 5 (70) Jun 29, 2011
I don't think in entanglement "something" travels from one particle to the other, so no need to postulate FLT. Both particles are considered components of the same single "thing" until "it's" broken up by interacting with another "thing", i.e. a measurement. Entangled particles are not two separate things communicating with each other.

We are confused because we can't get out of our own epistemological way. By virtue of obtaining intuitive understanding, we have subjected reality to a-priori conditions that are dependent on mind; i.e. we supply the conceptual structure necessary for intuitive understanding,... but nature Kan't be so confined.

Who are we to expect nature to function in ways compatible with how the mind has evolved to operate on the macroscopic scale. Bohr said just calculate,.. Einstein wanted nature to obey.
Noumenon
3.9 / 5 (67) Jun 29, 2011
,... so evidently at the quantum level a system is not confined to space or time as macroscopic experience has us evolved to understand.
Royale
not rated yet Jun 29, 2011
That always made me wonder. How does the fruit fly perceive time? For the fly does his 'full' 24 hours of life 'feel' like our average 60 or so years? Don't know if we'll have an answer in my lifetime, but I really long to know if time can be broken down into fractals. I.E. does the passage of time differ as things get way smaller and way bigger? I'm not talking about from our perspective, I'm talking about from the perspective of those larger and smaller things.
Noumenon
3.8 / 5 (66) Jun 29, 2011
Interesting. I have to reject the notion that time is a physical thing. Time is an intrinsic component of phenomenal reality, yes,.. but by definition 'phenomenal reality' is what is known by a mind, i.e. Reality as conceptualized. 'Phenomenal reality' must have a subjective component, as conceptualized reality is unlikely to be the same as unconceptualized reality. So, the mind in it's operation already presumes time and space as a means of being able to order experience. Time is an a-priori intuition, a relaton. There is no time 'particle' effecting things.
FroShow
3 / 5 (2) Jun 29, 2011
I'm confused: somehow the 'conversation' in the comments took a huge turn away from the article and subject at hand. As much as I enjoy hearing other people's ideas, its hard to make sense of them when there's little or no connections between them.
(I'll admit I opened the flood gates in asking if there are any particles that don't experience time other than photons... to which any responses were irrelevant to the question.)
Noumenon
3.9 / 5 (69) Jun 30, 2011
Yes, we should have stuck to Superman's Fortress of Solitude.

In answer to your question, no particles experience time as they have no conscious. Particles with zero mass travel on null geodesics so the spacetime interval is zero.

A unsnarky answer would be, the graviton is it exists and possibly the nutrino if it has no mass.
kaasinees
1 / 5 (4) Jun 30, 2011
Yes, we should have stuck to Superman's Fortress of Solitude.

In answer to your question, no particles experience time as they have no conscious. Particles with zero mass travel on null geodesics so the spacetime interval is zero.

A unsnarky answer would be, the graviton is it exists and possibly the nutrino if it has no mass.

A particle without mass is not a particle.
Noumenon
3.9 / 5 (69) Jun 30, 2011
Incorrect. A photon is a particle, however, keep in mind We are supplying the term particle or wave according to how a measurement is set up,... a measurement that is designed by a mind. Apart from Us, it's neither.
kaasinees
3 / 5 (5) Jun 30, 2011
Incorrect. A photon is a particle, however, keep in mind We are supplying the term particle or wave according to how a measurement is set up,... a measurement that is designed by a mind. Apart from Us, it's neither.

And a photon has mass. A photon does not have REST mass. The energy of the photon is equal to its mass.
Noumenon
3.9 / 5 (68) Jun 30, 2011
That is what is meant by massless. When can one use that term otherwise? Photons are massless. You don't need idea of mass to describe the energy or momentum of a photon, as it's proportional on frequency and wave number.
FroShow
2.8 / 5 (4) Jun 30, 2011
Yes, we should have stuck to Superman's Fortress of Solitude.
<-Snarky (or other appropriate word of your choosing)

In answer to your question, no particles experience time as they have no conscious.
<-Snarky? (C'mon, use your imagination, I'm sure you can correctly interpret what is meant in using the term 'experience'.)

Particles with zero mass travel on null geodesics so the spacetime interval is zero.
<-Clarification: the time component of it's spacetime vector is zero. It's spatial component is not. So, it's spacetime interval cannot be zero. Please elaborate on what idea you're trying to convey with this statement.

BTW, neutrino's DO have an extremely small but non-zero mass.
Noumenon
3.9 / 5 (66) Jun 30, 2011
Particles with zero mass travel on null geodesics so the spacetime interval is zero.

<-Clarification: the time component of it's spacetime vector is zero. It's spatial component is not. So, it's spacetime interval cannot be zero. Please elaborate on what idea you're trying to convey with this statement.


In SR the metric is Lorentzian, which means non positive definite. This means, depending on what signature one chooses, time is say -, which spacial plus . The interval is calculated as ds^2=dt^2 plus dx^2 plus dy^2 plus dz^2. Since the time signature is -, at c the interval is zero, for a observer. To a photon traveling across the universe there is zero distance and zero time.

[this comment edit does nof allow plus symbol]
Noumenon
3.9 / 5 (66) Jun 30, 2011
,.. so from the perspective of a photon, if it could experience, the path along a geodesic is one point.

Above I meant to say the spacial signature is plus while time is negative (-, plus, plus, plus ).
FroShow
3 / 5 (2) Jun 30, 2011
What I asked for, I received in the form of: "the graviton".
What I didn't ask for: a physics lesson elaborating on what I already knew.
Nonetheless; thank you. Because now, I too, can impress people with my new-found knowledge and direct conversations ever further away from their origins. (Snark!)
Noumenon
3.9 / 5 (65) Jun 30, 2011
Did you not post the following (?),...

the time component of it's spacetime vector is zero. It's spatial component is not. So, it's spacetime interval cannot be zero. Please elaborate on what idea you're trying to convey with this statement.


I responded as you clearly requested. Given your statement it's clear you didn't already know what I conveyed.

Why do you keep saying 'snarky'? I never described any of your post as such,... I admitted that I was being snarky!
FroShow
3 / 5 (2) Jun 30, 2011
Particles with zero mass travel on null geodesics so the spacetime interval is zero.
<-Clarification: the time component of it's spacetime vector is zero. It's spatial component is not. So, it's spacetime interval cannot be zero.

After further reading, I realize my comment is false. Apologies for any confusion caused.
Noumenon
3.9 / 5 (67) Jul 01, 2011
But I still get a 1 rating?
Royale
not rated yet Jul 01, 2011
Noumenon, you should know by now that unless there's at least 6 votes it's too hard to say what the general pop is feeling. Sort of makes me miss marjon (since he was almost always ranked consistently a 1) and Skeptic (although he's still around I don't see him much, and he's almost always ranked a 5).

But when two people are going back and fourth and there's one vote like that, we all know what's going on. Don't worry bout it. =)
FroShow
not rated yet Jul 01, 2011
yeah, I gave you a 1 rating, as you gave me a 1. mainly because the conversation was no longer appropriate for public debate, hence I sent you that PM explaining myself and my rising frustration at trying to make sense of what and why you wrote what you did. Also attempting to save others from needless babble. If you'd like to keep it public, I can do that. Though you're likely to regret it.
But I still get a 1 rating?
Didn't realize your ego was so tied up with your rating. I'll keep that in mind next time.
TheCyndicate
2.3 / 5 (3) Jul 03, 2011
Guys, you were getting it all wrong anyways. You were over-analyzing and not paying attention to basic information and principles.

For example, I said anything traveling AT 'C' or perhaps faster.

For some reason, you think that rule only applies to physical matter and I have no idea where you are getting this from.

In quantum entanglement, If I moved 1 entangled molecule, one direction, the other molecule will move the other direction, INSTANTLY. Now, lets say one molecule is on the other side of the Universe, it would still react INSTANTLY. This breaks lightspeed, because data is somehow transmitted to the other entangled particle.

EVERYTHING is governed by lightspeed. Including DATA in ANY format.

This is a clear violation.

BTW, I also completely agree that Time is not a physical dimension of any type and is only a human construct. Information like what is in this story, just helps to prove it.
Ulaanbatar
1 / 5 (4) Jul 03, 2011
Spacetime should be the simplest thing in nature, not some very complicated structure. Simplest is ideal gas and my ideal gas composed of the structureless speedy tachyons having velocity of 8.10^88C (C=Velocity of light in vacuum) leads to the experimental data, to the quantum mechanics, and to the SR and GR i.e. to the today's fundamental mainstream (NOT ultimate) theories.

Only tachyons (no matter whether bound in particles or free in spacetime) having, as a whole, eternal constant MEAN energy lead to the BASIC conservation law i.e. to the conservation law of energy. It leads also to the Principle of Relativity.

The tachyons lead to global nonlocality (Bohr wins with Einstein) and reality (Einstein wins with Bohr) of the Universe.

For more details view:-
http://www.cosmol...dSNT.pdf