Quantum Computing Interrupted

This is the second part of my write-up on my recent visit to D-Wave. The first one can be found here.

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The recent shut-down of the US government had wide spread repercussions. One of the side-effects was that NASA had to stop all non-essential activities and this included quantum computing.  So the venture which, in cooperation with Google, jointly operates a D-Wave machine was left in limbo for a while.  Fortunately, this was short lived enough to hopefully not have any lasting adverse effects.  At any rate, maybe it freed up some time to produce a QC mod for Minecraft and the following high level and very artsy Google video that 'explains' why they want to do quantum computing in the first place.

If you haven't been raised on MTV music videos and find rapid succession sub-second cuts migraine inducing (at about the 2:30 mark things settle down a bit), you may want to skip it. So here's the synopsis (Spoiler alert). The short version of what motivates Google in this endeavor, to paraphrase their own words: We research quantum computing, because we must.

In other news, D-Wave recently transferred its foundry process to a new location, partnering with Cypress Semiconductor Corp, a reminder that D-Wave firmly raised the production of superconducting Niobium circuitry to a new industrial-scale level.  Given these new capabilities, it may not be a coincidence that the NSA has recently announced its intention to fund research into super-conducting computing. Depending on how they define "small-scale" the D-Wave machine should already fall into the description of the solicitation bid, which aspires to the following ...

"... to demonstrate a small-scale computer based on superconducting logic and cryogenic memory that is energy efficient, scalable, and able to solve interesting problems."

... although it is fair to assume this program is aimed at classical computing. Prototypes for such chips have been already researched and look rather impressive (direct link to paper).  They are using the same chip material and circuitry (Josephson junctions) as D-Wave, so it is not a stretch to consider that industrial scale production of those more conventional chips can immediately benefit from the foundry process know-how that D-Wave has accumulated. It doesn't seem too much of a stretch to imagine that D-Wave may expand into this market space.

When putting the question to D-Wave's CTO Geordie Rose, he certainly took some pride in his company's manufacturing expertise. He stressed that, before D-Wave, nobody was able to scale superconducting VLSI chip production, so this now opens up many additional opportunities. He pointed out that one could, for instance, make an immediate business case for a high through-put router based on this technology, but given the many venues open for growth he stressed the need to chose wisely.

The capacity of the D-Wave fridges are certainly so that they could accommodate more super-conducting hardware. Starting with the Vesuvius chip generation, measurement heat is now generated far away from the chip. Having several in close proximity should therefore not disturb the thermal equilibrium at the core.  Geordie considers deploying stacks of quantum chips so that thousands could work in parallel, since they are currently just throwing away a lot of perfectly good chips that come off a wafer.  This may eventually necessitate larger cooling units than the current ones that draw 16KW. This approach certainly could make a lot of sense for a hosting model where processing time is rented out to several customers in parallel.

One attractive feature that I pointed out was that if you had classical logic within the box, you'd eliminate a potential bottleneck that could occur if rapid reinitialization and read out of the quantum chip is required, and it would also potentially open the possibility for direct optical interconnects between chips. Geordie seemed to like this idea. One of the challenges to make the current wired design work, was to design high efficiency low pass filters to bring the noise level in these connectors down to an acceptable level.  So, in a sense, an optical interconnect could reduce complexity, but clearly would also require some additional research effort to bring down the heat signature of such an optical transmission.

This triggered an interesting, and somewhat ironic, observation on the challenges of managing an extremely creative group of people.  Geordie pointed out that he has to  think carefully about what to focus his team on, because an attractive side project e.g. 'adiabatic' optical interconnects, could prove to be so interesting to many team members that they'd gravitate towards working on this rather than keeping their focus on the other work at hand.

Some other managerial headaches stem from the rapid development cycles.  For instance, Geordie would like to develop some training program that will allow a customer's technical staff to be quickly brought up to speed.  But by the time such a program is fully developed, chances are a new chip generation will be ready and necessitate a rewrite of any training material.

Some of  D-Wave's challenges are typical for high tech start ups, others specific to D-Wave. My next, and final, installment will focus on Geordie's approach to managing these growing pains.

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13 Responses to Quantum Computing Interrupted

  1. Sol Warda says:

    Henning:
    Thanks for the latest update on D-Wave. By the way, I love the idea (and have actually thought about it myself!) of stacking many chips to perhaps have one “cubic centimeter” chip consisting of tens of thousands, and eventually millions, of qubits working in parallel, all housed in a giant Black Cube!. THAT would be some supercomputer. Also, the arguments by the “Doubting Thomases”, that D-Wave is not “Quantum Computer”, are falling by the wayside, the last being “entanglement”, which has now been addressed by D-Wave scientists. Their lead theorist, Dr. Mohammad Amin, gave an abstract of this study at the Fields Institute of the University of Toronto in August of this year, and have sent the paper for publication. His abstract can be found here:

    http://www.fields.utoronto.ca/programs/scientific/13-14/CQIQCV/invited_speaker-abstracts.html

    • Henning Dekant says:

      Thank you for this interesting link. At this point I think there is little doubt that D-Wave harnesses true quantum effects, the evidence keeps piling up. So in a sense the outer defense line has fallen, the (rational) doubters had to retreat to the inner sanctum i.e. the question if this architecture will outperform classic computing resources. In a sense this is the perfect example for which the term “academic question” has been coined. And don’t get me wrong, for academic reasons this is very interesting, but the practical relevance is limited. Nevertheless, I may yet still lose my Maple Syrup :-)

      The abstract in your link perfectly illustrate the source for this contention and ongoing misunderstanding. Scott is clearly all about quantum complexity, whereas D-Wave is about bring a device to the market that for the first time manages to harness true quantum effects as a computational resource, and so gives practical proof that there is still plenty of room at the bottom (as Feynman so aptly put it)

  2. bettinman says:

    So Henning, how do your measure outperformance for your bet? is that calculations per dollars? or per watt?

    • Henning Dekant says:

      It is more straightforward in this context :-)

      It is pure annealing time on the current 512 qubit Vesuvius chip, versus CPU time single core of a classical machine, but no restrictions around how optimized and tailored the classical algorithm may be for the given problem scope. We are looking at 95% percentile significance for the bet to be decided. Power consumption does not factor in.

  3. JKW says:

    That barge at San Francisco Bay must be a quantum data center.
    Google’s involvement in any project spells trouble. World will never be the same. You will know what to think (and to buy) before you know it.

  4. rrtucci says:

    Google is going to make the Frisco barge disappear in plain daylight. They’re going to teleport it into another universe using Harmut’s multi-verse theory and D-wave’s QC. They’ve been practicing using qCraft. According to qCraft, it should work.

    • Henning Dekant says:

      You may be onto something, I can already see a movie script coming out of this, let’s call it the “San Francisco Experiment”, and for good measure have us throw some time travel in there while we’re at it :-)

  5. bettinman says:

    http://www.quantumheat.org/index.php/en/follow/follow-2/347-gamma

    Admin, off topic, but perhaps this warrants another thread on hot and cold fusion?

    • Too much hearsay rather than science even for my fringe spin-off :-)

      But Steven Krivit was so kind to alert me to his LENR Review published by Elsevier. If I find the time I may pull out some of the better references there to keep the likes of Popeye busy.

  6. Sol Warda says:

    Hi Henning: Since you recently visited D-Wave Systems HQ & met with its CTO, Geordie Rose, I assume that you are friends, or at least acquaintances now. For that reason, I think you are better situated to congratulate him, on his behalf and on behalf of his company’s supporters, for being named “one of 100 most influential people” by Foreign Policy Transfomational Trends. An article about this can be found here: http://www.marketwired.com/press-release/d-wave-systems-founder-cto-named-foreign-policy-magazines-100-leading-global-thinkers-1858899.htm

    Thanks for your time.

  7. rrtucci says:

    Henning, you Okay? Haven’t heard from you in a while.

    • Henning Dekant says:

      Thanks for asking. Are currently very much under the weather and have a looming work deadline. Started my GF post weeks ago but just can seem to find the time to finally finish it up.

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