Why We Need to Get Over “Quantum Supremacy”
There’s been a little excitement recently over Google claiming to have achieved quantum supremacy. Their computer, a 53-qubit chip called Sycamore, was claimed by John Martinis’ group to have performed a task in 200 seconds that a classical computer would have performed in 10,000 years. This, in essence, is what the term “quantum supremacy” is meant to refer to — an improvement in computing ability that changes what is possible. But this term, and even what it’s trying to refer to, has issues. It’s not clear that this improvement in technology will be beneficial, the term lends itself to hype, and it is strongly associated with the term “white supremacy”. I hope to make some of these problems clear.
Let’s start with technical issues. IBM was quick to say that Google’s claim underestimated the capability of classical computers. Their estimation is that the task could take 2.5 days without any help from quantum effects. This doesn’t mean that there aren’t any algorithms that would be made possible through the use of quantum computers, but it does serve as a cautionary tale for our excitement about what quantum computers might actually be useful for. This instance suggests we stay away from terms which can be easily hyped in media, as the technical picture is usually complicated.
What are quantum computers supposed to be “supreme” over? There are only a few algorithms that we can be reasonably confident will provide wild improvement, and they have very niche applications. The devices will always be specialized, high-resource machines. So, as pointed out by many, quantum computing can never replace classical computing. It (potentially) will add a new and complementary set of tools.
These tools are supposed to be world-changing. The promise of a new computing world at our fingertips: could we find new drugs through simulations? Could we simulate the world’s financial systems? Perhaps we could achieve unbreakable security! There are, unfortunately, reasons to be skeptical of all of these claimed applications. Simulating molecules, for instance, turns out to still be really hard on a quantum computer — and who would this help? Drug companies and the Canadian and American governments already seem pretty uninterested in ensuring that everyone has access to the medication they need.
Lastly on the technical front, let’s think for a minute about resources. Computing already presents massive resource usage in our society. Data centres alone in the US accounted for 2% of national electricity consumption in 2014. BitCoin transactions worldwide used more energy than Ireland did in 2017. Before they are turned on, computers are made from stuff. That stuff comes from the ground. It’s difficult to disaggregate this data based on what the materials are used for, but mining metals worldwide is estimated to account for 10% of climate change impacts. Many of the materials used in computers are additionally rare, hard to recycle, and leave behind radioactive waste. Our planet is finite. We are on a near-term world-destroying path. In examples of serious hype, there have been claims that quantum computers could help us to understand the climate crisis. Undoubtedly this is a goal we need to keep working towards, but we need that understanding and to drastically reduce global emissions now. Quantum technology is nowhere close to being able to provide this help, if it will ever be able, and in the meantime will require mining and energy-intensive fridges to function.
We’ve established several technical criticisms of the idea that quantum computers should be referred to as being able to achieve “supremacy”. Now, who are the people we are supposed to be communicating this to? Let’s say there are three groups: quantum scientists, non-quantum scientists, and financiers. Quantum scientists may be critical of the term for the reasons above. People who are not quantum scientists may, again, interpret this term as meaning that quantum computers will become ubiquitous, which is enormously unlikely. Financiers are an interesting group. Anecdotally speaking, every time I look up news about quantum computers I get results from Forbes and the Financial Times. Prominent researchers in the field are located at corporations like Google and IBM. It seems that the field is seen as important for the rich and powerful, that it’s something to invest in (though perhaps the quantum winter is coming). Every time a result is hyped, it encourages investment. This has benefits for researchers, but is it honest? Will it improve the field to pour venture capital money into it? Where does that money come from, and what kinds of expectations does it place on research? We have to acknowledge that we cannot rely on media to present results in cautious ways, and that the term “quantum supremacy” lends itself readily to hype.
Finally. Quantum and white supremacy. John Preskill coined the quantum term in 2012. A couple of weeks ago, he wrote, “supremacy, through its association with white supremacy, evokes a repugnant political stance. … In any case, the term caught on.” White supremacy has been a core tenet of global colonialism and genocide for centuries. America and Canada are settler colonial states built through genocide and slavery of Indigenous and Black people, and white supremacy continues to be a massive issue in the structures of these countries. There has been a resurgence of overt movements, perhaps exemplified by the Unite the Right rally in Charlottesville in 2017. But white supremacy is everywhere. And those engaged in anti-racism use and see this term all the time. Add to this the rampant racism within physics, tech, and academia, and it is no surprise that the quantum term evokes frustration for many. That a successful white academic came up with this term is not surprising. It speaks to his not being involved in anti-racist work. It reminds us that these fields are full of people who are not engaged with improving their actions or ways of thinking. Continuing on with using the term is a dismissal of anti-racist work and analysis and a sign that we are unwilling to address supremacy — unwilling to acknowledge the importance of Black lives or take steps to increase the safety of people of colour in North America or around the world.
Google itself is among many ultra-powered tech companies whose social media platforms and search engines have become tools of supremacists. They own YouTube, where algorithms inevitably lead towards radical content and supremacist groups post lengthy pieces of propaganda. Google seems to be fine with this. They’re doing well in a world built on inequality, so what motivations might they have to ask their quantum computing research group to back off on the dog-whistly terms?
Other terms have been proposed, including “quantum advantage”. I think this is still steeped in hype: we don’t have good evidence that much of an advantage will be provided by a computational speedup. I suggest we use a different term. Quantum technology has a lot to prove in order to be good to society. I am skeptical that it can be beneficial to most of us. We ought to consider the resources that it takes to produce this technology and be realistic about the benefits we can provide in a society which is already so unequal. If it can be shown, in that context, that quantum computers provide a genuine tool to be used in collaboration with classical computers, we could call it “quantum usefulness”. But before that, we need to show that this technology even has the potential to be beneficial. What this is really about is achieving “quantum non-uselessness”.