D-Wave’s Murray Thom explaining what’s going on inside the fridge in one of our systems.

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D-Wave’s Murray Thom explaining what’s going on inside the fridge in one of our systems.

Recently the Universities Space Research Association (USRA) announced that they were accepting proposals for computer time on the D-Wave system at the Quantum Artificial Intelligence Lab located at NASA Ames Research Center. Details are as follows, and you can find out more (and download the RFP) at USRA’s website at http://www.usra.edu/quantum/rfp/. We encourage researchers to take advantage of this opportunity.

*The Universities Space Research Association (USRA) is pleased to invite proposals for Cycle 1 of the Quantum Artificial Intelligence Laboratory Research Opportunity, which will allocate computer time for research projects to be run on the D-Wave System at NASA Ames Research Center (ARC) for the time period November 2014 through September 2015.*

*The total allocated computer time for the Cycle 1 research opportunity represents approximately 20% of the total available runtime during the period. Successful projects will be allowed to remotely access the quantum computer, and to run a number of jobs up to a maximum allocated runtime usage.*

*The Call is open to all qualified researchers affiliated to accredited universities and other research organizations. Exceptions to researchers unaffiliated with universities might be considered in case of proposals of outstanding quality and the desire to publish the results of the investigation. The computer time will be provided free of charge. No financial support is offered for the completion of the project.*

*Proposals are sought for research on artificial intelligence algorithms and advanced programming (mapping, decomposition, embedding) techniques for quantum annealing, with the objective to advance the state-of-the-art in quantum computing and its application to artificial intelligence.*

Colin Williams recently presented some new results in the UK. Here you can see some advance looks at the first results on up to 933 qubits. These are very early days for the Washington generation. Things will get a lot better on this one before it’s released (Rainier and Vesuvius both took 7 generations of iteration before they stabilized). But some good results on the first few prototypes.

One of the interesting things we’re playing with now is the following idea (starts at around 22:30 of the presentation linked to above). Imagine instead of measuring the time to find the ground state of a problem with some probability, instead measure the difference between the ground state energy and the median energy of samples returned, as a function of time and problem size. If we do this what we find is that the median distance from the ground state scales like where is the number of qubits, and is the number of couplers in the instance (proportional to for the current generation). More important, the scaling with time flattens out and becomes nearly constant. This is consistent with the main error mechanism being mis-specification of problem parameters in the Hamiltonian (what we call ICE or Intrinsic Control Errors).

In other words, the first sample from the processor (ie constant time), with high probability, will return a sample no further than from the ground state. That’s pretty cool.

Hi everyone! Sorry for being silent for a while. Working. :-)

Two interesting papers appeared on the arxiv this week, both from people at Ames working on their D-Wave Two.

First: A Quantum Annealing Approach for Fault Detection and Diagnosis of Graph-Based Systems

Second: Quantum Optimization of Fully-Connected Spin Glasses

Enjoy!

A new paper published today in Phys Rev X. It demonstrates eight qubit entanglement in a D-Wave processor, which I believe is a world record for solid state qubits. This is an exceptional paper with an important result. The picture to the left measures a quantity that, if negative, verifies entanglement. The quantity s is the time — the quantum annealing procedure goes from the left to the right, with entanglement maximized near the area where the energy gap is smallest.

Here is the abstract:

Entanglement lies at the core of quantum algorithms designed to solve problems that are intractable by classical approaches. One such algorithm, quantum annealing (QA), provides a promising path to a practical quantum processor. We have built a series of architecturally scalable QA processors consisting of networks of manufactured interacting spins (qubits). Here, we use qubit tunneling spectroscopy to measure the energy eigenspectrum of two- and eight-qubit systems within one such processor, demonstrating quantum coherence in these systems. We present experimental evidence that, during a critical portion of QA, the qubits become entangled and entanglement persists even as these systems reach equilibrium with a thermal environment. Our results provide an encouraging sign that QA is a viable technology for large scale quantum computing.

Here’s a neat paper from UCL and USC researchers ruling out several classical models for the D-Wave Two, including the SSSV model (“…the SSSV model can be rejected as a classical model for the D-Wave device”), and giving indirect evidence for up to 40 qubit entanglement in a real computer processor.

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