We demonstrate that the performance of a quantum annealer on hard random Ising optimization problems can be substantially improved using quantum annealing correction (QAC). Our error correction strategy is tailored to the D-Wave Two device. We find that QAC provides a statistically significant enhancement in the performance of the device over a classical repetition code, improving as a function of problem size as well as hardness. Moreover, QAC provides a mechanism for overcoming the precision limit of the device, in addition to correcting calibration errors. Performance is robust even to missing qubits. We present evidence for a constructive role played by quantum effects in our experiments by contrasting the experimental results with the predictions of a classical model of the device. Our work demonstrates the importance of error correction in appropriately determining the performance of quantum annealers.
Five months ago, I received an email and then a phone call from Google’s Creative Lab Executive Producer, Lorraine Yurshansky. Lo, as she prefers to be called, is not your average thirty year-old. She has produced award-winning short films like Peter at the End (starring Napoleon Dynamite, aka Jon Heder), launched the wildly popular Maker Camp on Google+ and had time to run a couple of New York marathons as a warm-up to all of that. So why was she interested in talking to a quantum physicist?
You may remember reading about Google’s recent collaboration with NASA and D-Wave, on using NASA’s supercomputing facilities along with a D-Wave Two machine to solve optimization problems relevant to both Google (Glass, for example) and NASA (analysis of massive data sets). It was natural for Google, then, to want to promote this new collaboration through a short video about quantum computers…
Cakebread will further manage and help sustain balance in D-Wave’s corporate expansion trajectory as it pursues its mission to solve the intractable problems of industry, security, aerospace and medicine. Before joining D-Wave, Cakebread served as chief financial officer of Pandora Media, Inc., a provider of personalized Internet radio and music discovery services. He was president and chief strategy officer of salesforce.com, a customer relationship management service provider. Other roles with salesforce.com include executive vice president and chief financial officer. Before that, Cakebread served as senior vice president and chief financial officer at Autodesk and Silicon Graphics World Trade. Cakebread holds a B.S. in business from the University of California at Berkeley and an M.B.A. from Indiana University.
“It’s a privilege to be part of the next big leap in computing,” stated Cakebread. “Classical processors have a new partner and there’s no limit to how far humanity can advance with the power of quantum computers. Clearly, D-Wave is leading this next generation of computing.”
New paper published in Phys Rev B last week showing a very cool new technique for examining quantum effects in big quantum systems. Here’s the arxiv link.
Here is the abstract:
We describe a quantum tunneling spectroscopy technique that requires only low bandwidth control. The method involves coupling a probe qubit to the system under study to create a localized probe state. The energy of the probe state is then scanned with respect to the unperturbed energy levels of the probed system. Incoherent tunneling transitions that flip the state of the probe qubit occur when the energy bias of the probe is close to an eigenenergy of the probed system. Monitoring these transitions allows the reconstruction of the probed system eigenspectrum. We demonstrate this method on an rf SQUID flux qubit.
Keen-eyed readers may have noticed a new section on the D-Wave website entitled ‘developer portal’. Currently the devPortal is being tested within D-Wave, however we are hoping to open it up to many developers in a staged way within the next year.
We’ve been getting a fair amount of interest from developers around the world already, and we’re anxious to open up the portal so that everyone can have access to the tools needed to start programming quantum computers! However given that this way of programming is so new we are also cautious about carefully testing everything before doing so. In short, it is coming, but you will have to wait just a little longer to get access!
A few tutorials are already available for everyone on the portal. These are intended to give a simple background to programming the quantum systems in advance of the tools coming online. New tutorials will be added to this list over time. If you’d like to have a look you can find them here: DEVELOPER TUTORIALS
In the future we hope that we will be able to grow the community to include competitions and prizes, programming challenges, and large open source projects for people who are itching to make a contribution to the fun world of quantum computer programming.