Quantum Supremacy

01/11/2019

Google recently announced that they have reached an important landmark in quantum computing: a quantum computer that can solve a problem that a classical computer would not be able to solve in any practical timeframe. As published in the science journal Nature, Google reports that its latest quantum computing chip was able to perform a calculation in 200 seconds that would have taken a classical supercomputer 10,000 years to complete.

This has been hailed by some as evidence of a quantum computer exhibiting “quantum supremacy” – a state in which a quantum computer massively outperforms the world’s most powerful supercomputer.

Quantum supremacy is made possible, at least in theory, by the behaviour of qubits – the quantum analogue to classical bits. Unlike classical bits that must take a value of either 0 or 1, qubits can exist in a state of 0, 1, or in a superposition of both states. This property of the qubit can be utilised in quantum computing for massive parallel processing of information, which can vastly improve processing power.

Google’s impressive achievement is proof of this concept and is an exciting step in bringing quantum computers to commercial reality.

However, it should be noted that Google’s test relates to solving a specific problem that is designed to provide proof of concept; it is not designed to be practically useful. Whilst undoubtedly an important milestone, there is still some way to go before quantum computers start making their way into our day-to-day lives. Indeed, the next step from here is to show quantum supremacy in applications that have scientific or commercial utility, and this is still a significant challenge.

That being said, important progress is evidently being made in this area, and it is interesting to see that this progress is being spearheaded by big commercial players such as Google and IBM.

What is more, this seems to be part of a broader trend of business investment into quantum technology as a whole. For example, a number of recent studies that have looked at patent filing trends in quantum technology – see for example the article I wrote on this subject in 2017 (which can be found here) – have found a general upward trend in the number of patent filings in this area year-on-year in the last two decades. Whilst the specific filing numbers vary somewhat depending on the particular study (a natural consequence of differences in search methodologies, for example the search terms used, countries looked at, etc.), the fact that the general trend points upwards is a reasonable indicator of increasing commercial interest.

We are still not at the point at which revolutionary quantum products are hitting the shelves. However, it seems that businesses are increasingly turning their attention to this area, ramping up investment in technology development and filing patent applications to protect the resulting innovation.

It is too early to gauge exactly what impact this will have on the wider world – the technology is still too green. However, the promise is great, as Google’s latest test has shown.