

New Google lab working on quantum computing hardware - finisterre
http://www.technologyreview.com/news/530516/google-launches-effort-to-build-its-own-quantum-computer/

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ridgeguy
I hope Martinis considers NV (nitrogen vacancy) centers in synthetic diamond
as quantum computing elements.

There's considerable work that indicates diamond NV centers could be valuable
in the next step beyond D-Wave's systems. A few of many:

Photonic Architecture for Scalable Quantum Information Processing in Diamond
[http://arxiv.org/abs/1309.4277](http://arxiv.org/abs/1309.4277)

Quantum Correlation Between Distant Diamonds
[http://www.sciencemag.org/content/334/6060/1213.summary](http://www.sciencemag.org/content/334/6060/1213.summary)

Quantum computing: Diamond and Silicon Converge
[http://211.144.68.84:9998/91keshi/Public/File/34/479-7371/pd...](http://211.144.68.84:9998/91keshi/Public/File/34/479-7371/pdf/479047a.pdf)

Homoepitaxial Growth of Single Crystal Diamond Membranes for Quantum
Information Processing
[http://dash.harvard.edu/bitstream/handle/1/11859326/Homoepit...](http://dash.harvard.edu/bitstream/handle/1/11859326/Homoepitaxial%20Growth%20of%20Single%20Crystal%20Diamond%20Membranes%20for%20Quantum%20Information%20Processing_arxiv.pdf?sequence=1)

~~~
gaze
"I hope Martinis considers NV (nitrogen vacancy) centers in synthetic diamond
as quantum computing elements." He's built his career around superconducting
circuits. Switching to optics would put him outside his area of expertise, so
it's unlikely.

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bkcooper
I'm pretty intrigued by this. Martinis is very good, and I already thought it
was interesting when I saw earlier today that Google had picked him up. That
he will be trying to improve D-Wave style designs (by dropping in transmons,
from the sound of this article) is not at all what I would have guessed.

I think that will be fairly tough. It's been a while since I looked at D-Wave,
but aside from the whole "is it quantum" question about their stuff, their
fabrication always seemed like a real strength. They had tons of on-chip
circuits for addressing all of the qubits, and building devices with that many
Josephson junctions that work is not easy. The comment that some of their
material choices are probably limiting coherence is almost certainly true
(this was one of Martinis's big contributions from ~10 years ago). But
translating processes of that complexity to cleaner setups seems like it's
going to require some real fabrication fu. I certainly wouldn't put it past
Martinis, but it's ambitious for sure.

~~~
gaze
I'd be happy if he just does science on the system. Maybe he can figure out a
way to zeno the system into being classical to prove a speedup.

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ghshephard
For the uninitiated in quantum computing requirements - this jumped out at me:

 _Martinis makes his qubits from aluminum circuits built on sapphire wafers
and chills them to 20 millikelvin_

I wasn't even aware that "millikelvin" was a thing.

~~~
archgoon
Millikelvin _is_ quite cold. 2 mK is the limit of dilution refrigeration
technologies (achieved by mixing the liquids Helium-3 and Helium-4), so 20 mK
is about the best you can do continuously. Since they want to operate a device
for an unspecified amount of time, this is probably what they're going with.

[http://en.wikipedia.org/wiki/Dilution_refrigerator](http://en.wikipedia.org/wiki/Dilution_refrigerator)

That said, if you're willing to consider non-continuous cooling methods such
as laser cooling, then you can get quite a bit colder.

Back in 1995, the first Bose Einstein Condensate was created in a laboratory
by achieving a temperature at about 1 microkelvin.

[http://cua.mit.edu/ketterle_group/Projects_1995/Pub_95/davi9...](http://cua.mit.edu/ketterle_group/Projects_1995/Pub_95/davi95-PRL03969-bec.pdf)

(that's the paper that summarizes the results that won the 2001 Nobel Prize in
Physics)

However, in 2003, the coldest temperature of a full system was achieved when a
group at MIT cooled a BEC down to 500 picoKelvin (half a billionth of a
Kelvin).

[http://www.sciencemag.org/content/301/5639/1513.abstract](http://www.sciencemag.org/content/301/5639/1513.abstract)

That said, if you're willing to cut some hairs and only count _part_ of a
thermal system (say, the nuclear spins of rhodium atoms), then you can count
Tauno Knuuttila's achievement of 100 picokelvin.

[http://lib.tkk.fi/Diss/2000/isbn9512252147/](http://lib.tkk.fi/Diss/2000/isbn9512252147/)

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kul_
Hey no more log(N) for me plz!

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nn3
So someone's vaporware is claiming to be better than a shipping system?

<yawn>

The article seemed to be very unbalanced. Normally you would expect at least a
quote from the Dwave side.

~~~
vidarh
The article does not claim that "someone's vaporware" is better than a
shipping system. It states that they believe there may be opportunities in
doing things differently. With no promises that they'll manage to do better.
There's nothing of substance there for D-Wave to respond to. _Of course_ there
are opportunities in doing things differently.

