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A Simple Experimental Challenge?

Commenter Michael J. Biercuk asks about D-wave’s machine:

What is the fundamental experimental test which would demonstrate the system is not simply undergoing a classical, incoherent process?

Of course there are answers to this question which involve some technically fairly challenging experiments (proving that a quantum computer is quantum computing is something which many experimentalists have struggled over, for far smaller systems than D-wave’s system.) But there is a much simpler experiment which I haven’t seen answered in any of the press on D-wave, and which, for the life of me, I don’t understand why it hasn’t been done and publicized.
Continue reading “A Simple Experimental Challenge?”

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D-Wave Talk

So did anyone at MIT go to this talk and care to comment:

Mohammad Amin (D-Wave)
Adiabatic Quantum Computation with Noisy Qubits
Adiabatic quantum computation (AQC) is an attractive model of quantum computation as it may naturally possess some degree of fault tolerance. Nonetheless, any practical quantum circuit is noisy and one must answer important questions regarding what level of noise can be tolerated. Gate model quantum computation relies on three important quantum resources: superposition, entanglement, and phase coherence. In this presentation, I will discuss the role of these three resources and the effect of environment upon them with respect to AQC. I will also show a close relation between open AQC and incoherent tunneling processes as in a double-well potential. At a more microscopic level, I will present a non-Markovian theory for macroscopic resonant tunneling, together with recent experimental results on superconducting flux qubits which demonstrate excellent agreement with the theory and may shed light on the microscopic origin of flux noise in these devices. Finally, I will discuss the effect of low and high frequency noise on practical AQC processors and compare AQC with thermal annealing.

Update (11/21/07): Geordie Rose has put the slides of the talk online at this blog post. I’ll have to look at them while eating Turkey.

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What a Canadian STOC Deadline Looks Like

Here is a picture I call “STOC 2008 deadline”:
STOC 2008 will be in Victoria, British Columbia. I was just across the border in Surey, BC, and shot this picture which I call “Crazy Canadian Fireplace Channel”:

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Chemical Pontiff

Will the real quantum pontiff please stand up? From the Taiwan Journal:

Lee Yuan-tseh, a Taiwanese-born scholar and the 1986 Nobel Prize laureate in chemistry, was named Oct. 9 as a new member of the Pontifical Academy of Sciences by Pope Benedict XVI. He is the fourth ethnic Chinese scientist to receive this honor.

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Cryptosystem Insecurity Season

Seems it ’tis the season for warnings about the security of cryptosystems. The New York Times has an article on the latest issue here. It seems that Adi Shamir (the S in RSA) has a note out describing how faults in chip hardware could render cryptosystems insecure. It’s not at all clear to me how this differs from analysis where the faults are injected into the hardware (such as described here) because the article doesn’t contain any real details.