by Aletta Meinsma

On October, 2019, the news got picked up widely: “Google Claims a Quantum Breakthrough That Could Change Computing” headlined The New York Times (Metz, 2019). “Google claims ‘quantum supremacy’ for computer” according to the BBC (Rincon, 2019). The Google researchers themselves titled their paper: “Quantum Supremacy Using a Programmable Superconducting Processor” (Arute et al., 2019). They claimed to have reached a milestone in quantum computing: using 53 functional qubits, they performed a task in 200 seconds that they said would take the world’s best supercomputer about 10,000 years to complete. (At our QuTech blog, we also published a post about it here.)

However, not long after the news came out, IBM started contradicting the claim that Google made. They argued that Google’s quantum computer managed to solve a task that would take their supercomputer only 2.5 days to complete instead of those 10,000 years (Pednault, Gunnels, Maslov, & Gambetta, 2019). This left us with the question: does this change anything? Has quantum supremacy been reached, or is the race to becoming the first one to reach quantum supremacy still on?

Well, some people argued something else: that the race to reach ‘quantum supremacy’ should be completely off the table (Palacios-Berraquero, Mueck, & Persaud, 2019).

Before you get worried, these people are not saying that we should wave the research on achieving quantum supremacy goodbye – it’s about the term ‘quantum supremacy’ itself.

Criticism on ‘quantum supremacy’

In 2012, John Preskill first proposed the term ‘quantum supremacy’ to refer to the point at which a quantum computer could outperform a classical computer. “With that new term, I wanted to emphasize that this is a privileged time in the history of our planet, when information technologies based on principles of quantum physics are ascendant” (Preskill, 2019).

However, criticism on the term ‘quantum supremacy’ has been growing ever since (Wiesner, 2017; Palacios-Berraquero et al., 2019; Durham, Garisto, & Wiesner, 2021; Roberson, 2021). First of all, “supremacy” has a negative connotation in multiple languages. For the English language, the two-word collocate “white supremacy” occurs 15x more often than “judicial supremacy”¹, which is the secondly most common two-word collocate of supremacy (Durham et al., 2021). Also, in the Dutch language, the translation of “white supremacy” is one of the most common two-word phrases of supremacy². White supremacists believe that white people are genetically superior, have a superior culture and should have dominance over other racial groups. The politics of it have led to discrimination and racial segregation in the past, for example during the Apartheid regime in South Africa between 1948 and 1991 (Wiesner, 2017).

A second point of criticism is illustrated exactly in the disagreement between Google and IBM: when can you rightfully claim to have reached quantum supremacy (Sanders, 2021)? Should the task that a quantum computer solves really be out of reach for a classical supercomputer? Or is it already enough if a quantum computer solves a task significantly more efficient, either in time, or in processing steps? Moreover, how can we know if the actual optimal classical algorithm is being compared to the quantum algorithm?

Finally, the third point of criticism is one that John Preskill said to have anticipated (Preskill, 2019). The term ‘quantum supremacy’ could potentially exaggerate quantum technologies, resulting in overhype. Google’s quantum computer solved a task that has no practical uses yet and could only solve it correctly once every 500 times. Currently, the milestone seems to be of academic value only (Roberson, 2021). Furthermore, the term could make people believe that quantum computers outperform classical computers on all tasks, that they are superior on all tasks, making classical computers redundant (Durham et al., 2021). As also explained in this blog post, this is currently not the case.

Should scientists be careful about their use of language?

Are these points of criticism severe enough for us to indeed say goodbye to the term ‘quantum supremacy’?

The Editorial Board of the Wall Street Journal doesn’t think so (The Editorial Board, 2019) and neither does Canadian-American linguist and popular science author Steven Pinker (Pinker, 2019). Both commented on an article in Nature that asked the quantum community to move away from the term (Palacios-Berraquero et al., 2019). The Wall Street Journal argued that “mankind has hit quantum wokeness. Our species, akin to Schrödinger’s cat, is simultaneously brilliant and brain-dead. We built a quantum computer and then argued about whether the write-up was linguistically racist”. Pinker added that “word meanings are conventions, not spells with magical powers, and all words have multiple senses, which are distinguished in context….”

Durham, Garisto, & Wiesner (2021) disagree. According to them, The Wall Street Journal and Pinker don’t take into account the context in which the word was invented: quantum research is historically a white, male-dominated discipline. “If the charge to take back “quantum supremacy” were led by Black scientists and other underrepresented minorities in physics, that would be one thing. No survey exists, but anecdotal evidence suggests this is decidedly not the case.”

Research teams adopt new term: ‘quantum computational advantage’

Although the term is still disputed, reaching ‘quantum supremacy’ has remained an active area of research. In December, 2020, a Chinese team published an article stating that their photonic quantum computer could solve a task ~10¹⁴ times faster than a classical supercomputer would be able to do (Zhong et al., 2020). Last October, 2021, the same Chinese team had been able to increase the factor to ~10²⁴ (Zhong et al., 2021), while another Chinese achievement involved a superconducting quantum processor finishing a task in 1.2 hours that they claimed would take a classical supercomputer 8 years to complete (Wu et al., 2021).

In all these three Chinese papers, the scientists avoided the use of ‘quantum supremacy’ and instead adopted the term ‘quantum computational advantage’. Similarly, the term ‘quantum advantage’ was suggested in an article in Nature (Palacios-Berraquero et al., 2019). John Preskill, though, rejected this alternative, saying (Preskill, 2019): “[..] to me, “advantage” lacks the punch of “supremacy”. In a race, a horse has an advantage if it wins by a nose. In contrast, the speed of a quantum computer vastly exceeds that of classical computers, for certain tasks. At least, that’s true in principle.”

Are there other alternatives?

So – suppose we indeed reject the term ‘quantum supremacy’, but agree with John Preskill that ‘quantum advantage’ does not accurately describe the achievement. Is there another term we can adopt?

Well, yes there is. We actually have the luxury to choose from many other alternatives. Over the years, terms that got proposed include “quantum ascendancy”, “quantum non-uselessness”, “Noisy Intermediate Scale Quantum computing”, “quantum practicality” and “quantum primacy”³ amongst others (Fulton, 2020; Durham et al., 2021). The last term popped up in several news articles mentioning the latest Chinese achievements (Sanders, 2021; Yirka, 2021; Dunhill, 2021). Primacy means ‘the condition of being first’, and the scientists that proposed this term “believe [it] succinctly captures the scientific implications with less hype and—crucially—no association with racism” (Durham et al., 2021).

At IQT Europe in 2020, Lieven Vandersypen, our Scientific Director, also got involved in the discussion. He mentioned to favor the term thought of by James Clarke from Intel: ‘quantum practicality’. As Clarke put it, it refers to “getting quantum out of labs and into the real world, where it can solve real problems” (Fulton, 2020).

Do you have an opinion?

What is your view on this discussion? Has the discussion deteriorated to an absurd level of ‘quantum wokeness’? Or is it absurd that racists elements are part of a quantum scientist’s language? Should we need to adopt an alternative term, like ‘quantum primacy’ or ‘quantum practicality’?

Should we say goodbye to ‘quantum supremacy’?

Aletta Meinsma is one of the newest members of the blog editorial team and decided to celebrate fittingly by writing a blog post.

In her PhD, she combines two relatively young research fields – science communication and quantum technology, at two relatively old universities – Leiden University and TU Delft. With Julia Cramer as supervisor and Ionica Smeets and Ronald Hanson as promotors, she intends to research how to bridge the gap between quantum technologies and society. When you cannot find her at either of the two universities, she’s probably running somewhere in Delftse Hout or endlessly practicing Christmas songs on her piano (currently).

Footnotes

1. Based on the Corpus of Contemporary American English, containing more than one billion words from texts of different genres.
2. Based on the Corpus Hedendaags Nederlands, containing more than 800.000 Dutch texts.
3. Note that these terms subtly differ in meaning.

References
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Corpus Hedendaags Nederlands. (2021). Retrieved from https://ivdnt.org/corpora-lexica/corpus-hedendaags-nederlands/
Dunhill, J. (2021, November 1). Chinese Scientists Create Quantum Processor 60,000 Times Faster Than Current Supercomputers. Retrieved from https://www.iflscience.com/
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