Michio Kaku is one the leading brand names in popular science writing and has written on numerous subjects, but of course, with a bent towards his specialist area of physics. Kaku now turns his attention towards Quantum Supremacy or, as some people have renamed it: “Quantum Advantage”. In his latest book, published in May 2023, Kaku provides an overview of the nascent area of quantum computing and quantum technology.
We covered Kaku in our article on the leading futurists, and his latest work is quite a gentle introduction to a range of scientific advancements posited as being potentially disrupted by quantum technology. The book provides quite a good review of various technologies, such as CRISPR, The Environment, Materials & Chemistry and how Quantum could enhance each of these fields.
Kaku touches on other use cases, such as optimization, as utilized by automotive companies such as Ford and GM, who have demonstrated using a quantum optimization process for routing vehicles. Much of these have been demonstrated by hardware from D-wave and their Quantum Annealers.
Fundamentally, you might think Quantum could improve every scientific and technological endeavour, but that would be fallacious. We only know of specific algorithms that are theoretically amenable to being sped up or enhanced by quantum algorithms. There is even a quantum zoo of algorithms highlighting quantum algorithms and their potential speed-ups.
By theoretical, we would need a quantum machine with enough resources, qubits or quantum volume (a metric Introduced by IBM). Currently, the state-of-the-art quantum means less than 500 qubits (IBM has 433 qubits that it sports in its latest machine). Other machines have more sedate numbers of qubits, ranging anywhere from single digits to low hundreds.
Even if you think it is a lot, consider that error correlation might reduce that number of qubits by several orders of magnitude – and in some cases, by as much as 1,000 (3 orders of magnitude). That means that, according to some researchers, we are still at the stage of creating a single error-corrected qubit.
PsiQuantum has suggested they target a million qubits, giving roughly 1,000 logical qubits to build quantum circuits. It might sound a lot, but your typical Apple M1 chip has 16 billion transistors! We’ll likely crack 1,000 qubits very soon, but that doesn’t give a lot that can be achieved as far as the implementation of the “sexy” or exciting circuits that complexity theorists have shown have a quantum advantage for (and that there is no better classical algorithm that we have yet to discover).
In his latest talk at the Economist Conference on Commerclaising Quantum, Richard Moulds provides sufficient caution against the hype machine. Moulds is head of Bra Ket which is Amazon’s Quantum Platform which offers quantum computing as a service in the cloud agnostically from a range of Quantum Hardware suppliers. Amazon builds the services and creates that market just as it did with AWS, and we might read between the lines that, just as with AWS, users will find interesting potential use cases just as has happened with AWS.
There is always a danger when discussing the potential benefits of Quantum technology that it becomes a panacea or a cure for everything. We must be careful that the word “quantum” doesn’t become a prefix for any technology marketers want to push. Unlike, say, a faster CPU, Quantum is a radically different way to perform computation, and therefore, we cannot expect to get a new CPU chip and speed up everything. Only specific algorithms will likely ever show a quantum advantage; of course, we may find more, but right now, only certain particular operations can be (theoretically) run faster on a quantum machine than on a traditional or classical machine. Scientists still need to work on how to get data encoding working and Quantum RAM (QRAM) into reality.
In the future, researchers may find more uses for quantum computers, but we, as responsible scientists, must be mindful of the hype surrounding Quantum Computing. We have to be careful that quantum computing does not get over-promised and under-delivered. It is not a general computing technique. Now is the time to experiment, play and develop some of the foundations of quantum technology without excessive expectations.
So if you want to review some of the emerging technological and scientific fields around the world in the science and technology labs, then this popular science book provides a gentle overview. But don’t expect Quantum to have an impact on these fields suddenly. One day hopefully, yes, but there is still a considerable gap, something that may not be eminently clear to readers.
Experiment, Play, and Explore, But don’t expect a Quantum Everything Future (just) yet.