Quantum Computing —What’s it All About

Welcome

Are you quantum curious? Do you have a nagging feeling quantum computing is important but aren’t sure why? Are you always thinking about how your company could use data better? Do you want to be ready for the next tech revolution? Then this is the right place for you.

Quantum computing as a serious business topic is new. Yes, it’s complicated and it has a lot of unknowns, but you are entirely right to invest some time to understand it better. If this were a LinkedIn article it would say “Reading time: 30 minutes”. If you’d had the chance in 1995 to spend 30 minutes reading about the internet, or 30 minutes to read up on social media in 2000, or smartphones in 2005, that would have been time well spent. These next 30 minutes are equally important here in 2021 for how your company will be operating in 5 or 10-years’ time.

This primer is aimed at those with little or no technical knowledge. It will help you understand enough about quantum computing to judge how and when you should be ensuring your organisation is discussing the topic. It will answer some basic questions and help you as your start to plan your road towards quantum readiness.

I’ve written it exactly as I would have liked to read it twenty-four months ago when I was new to this topic and set up Quantum London to investigate the business impact of this fascinating new(ish) technology. I had to ask a lot of daft questions and fight through far too many deep-tech explanations. I’ve now reached the step on my personal quantum journey where I feel I can explain enough of the basics to you to be helpful. It’s purposefully short: there’s no excuse not to finish it and no reason why you can’t understand every word and idea.

In thirty minutes (or an hour if you decide you need to re-read as you reflect) you’ll have enough information to decide whether you want to investigate the topic further. You’ll then be ready to engage with the growing world of books, websites, associations, and other means to find out much, much more.

Following this introduction, the pamphlet is split into three main sections:

1. What’s it all about

2. How it may make a difference

3. Why the usual excuses to put it off don’t fly here

I considered whether to include a detailed appendix for those who want more information. I’ve decided against this. I want you — the reader — to feel that you have confidently finished the whole document and are able to already start making decisions. You should be rewarded with a real sense of achievement in finishing, rather than sighing as you stare with horror at a detailed appendix which, however well written, may not fully make sense.

Paolo Cuomo

Sevenoaks, UK

This article is split into three

1. Introduction (this post)
2. Why QC is useful and potential business applications (link to be added once published)
3. Why busy executives should engage with the topic (link to be added once published)

Or read the ebook (or paperback) here - US & International link, UK link

Why are we here?

From thought-experiment to the next paradigm-changing tech

The concept of quantum computing has been around for some decades. What’s changed in the last few years is that technical breakthroughs mean we can be confident “it works”. And thus, the question becomes not ‘if’ but ‘when’ quantum computing will be part of how we manipulate data and solve problems.

In several decades' time, we won’t get excited about quantum computing. In the same way that now, less than twenty years since we heard the terms 3G and broadband for the first time, we are no longer obviously impressed that we can transmit massive amounts of data to mobile devices or television screens. The use of quantum computing will be as transformational and ubiquitous as the use of mobile data and broadband internet are today. And in the same way, it will become over time just as ‘behind the scenes’ for most users.

However, as with any new technology, the transition point is where those who plan ahead and position their firms appropriately have the chance to benefit from small changes faster than the competition. The breadth and depth of the impact of quantum computing means we’ll be in an overall transition phase for several decades. However, for each specific industry and use-case the transition will take place in a tighter space of time, amplifying the potential gains for some, but shortening the duration they can maintain their advantage.

As such, the key aim of this short primer must be to educate you on the concept of quantum readiness and share some questions for you to start to consider as you define your quantum readiness posture.

Quantum computing and the hacking of the internet

There’s an important side point to make here before we start as it may be what drew you to the topic. That’s the role of quantum computing in breaking encryptions and decrypting confidential data. This is a clear and present danger to everyone who uses data. Clear because the current progress of hardware development suggests that many of the most common encryption techniques will not withstand quantum computers within a decade. Present because any major upgrade to IT and communications systems takes years, so work must start before the threat manifests itself, not simply when the first attacks are successful.

This risk is real and important and requires Chief Risk Officers, Chief Information Officers and Chief Information Security Officers to develop plans and implement them. I do not however want this zero-sum, defensive activity to distract from the key intent of this book which is the opportunity quantum computing brings.

As such I will avoid any mention, aside from a brief paragraph at the end, and instead point you towards the various communities we have set up in Quantum London to discuss quantum-as-a-risk, which can share detailed, action-orientated plans.

Focus on the positive opportunities not the narrow negatives

QC offers the promise of a far more efficient and effective future: supply chains truly optimised — saving time, money, and fuel; energy grids and traffic-light networks redesigned — increasing resilience, saving time, reducing pollution; creation of new materials for batteries, redesign of manufacturing processes and discovery of new life-enhancing drugs.

Of course, quantum computing doesn’t achieve this on its own. It is as a tool for smart, driven individuals and corporations through whom these changes can be achieved. I hope professionals and executives focus on these possibilities rather than being overly distracted by the decryption risks.

Quantum Computing: So, what actually is it?

A tech view

Quantum computers are a new type of computer that do calculations in a fundamentally different way. They will do certain calculations dramatically faster than current computers can. This will allow some business questions we currently answer infrequently to be answered faster and more often. It will also allow us to ask some questions we previously considered impossible to answer. And, as with any new technology, as we become clear on the capabilities, it will let us ask (and answer) questions that we had previously not even considered; solving the unknown unknowns, if you will.

The clearest I’ve seen this concept laid out is in a simple diagram such as the below. The first time I saw this was an excellent presentation given by IBM’s Andy Stanford-Clark to Quantum London called “Quantum Computing: a guide for the perplexed”. A fitting title and fascinating talk.

The most visible scientific and engineering feats in this field at the moment are the designing and building of the quantum computing hardware. What’s most important for you though is not the physical computers themselves but the software and algorithms that other — equally impressive — technologists are now developing.

That said, we do need a brief diversion into what is going on with the underlying technology

It’s all about qubits

All current computers (except the 100 or so quantum computers already built) use bits. Bits are 1s or 0s. Anything you do on your computer, your phone, or though the systems in your car or microwave turn instructions into a series of 1s and 0s. These are processed to give an output that then triggers an action or shows something on a screen. Computers have been operating like this since (and before) the invention of the transistor and the microchip half a century ago.

The 1 or 0 feature means bits can represent one of two states. To get four states you need two bits, while three bits gives you eight states. (If you had eight different products in inventory you could give them each a unique code: 000, 001, 010, 011, 100, 101, 110, 111). This binary way of working is perfect for the way our current ‘classical’ computers work. Each bit is limited, so to deal with large amounts of data computers use lots of bits and lots of microchips in parallel.

Qubits — Quantum bits — are fundamentally different as a qubit operates in a way that can have far more than just two states. There are ways to explain this in non-mathematical ways that smart laypeople might just get their head around. I’m not going to do that in order to reinforce my point that you don’t need to understand the tech. Just like you don’t need me to explain the way mobile phones sends control signals every time you move between different radio masts when driving on the highway, nor how the heck engineers get a billion transistors on a microchip, or in fact the 100-year old design of a car’s internal combustion engine.

The two things you do need to know about qubits is that (a) more qubits give you more computing power, and (b) not all qubits are created equal, so someone’s headline around a “250 qubit” machine may be less powerful than another company’s “150 qubit” device.

Moving beyond HPC

Supercomputers, often referred to as high-performance computing (HPC), allow us to manipulate unfathomably large amounts of information for predicting the weather, modeling nuclear explosions, exploring for oil, and so on. As with the geopolitical game of “who’s got the tallest skyscraper”, there is a constant to-ing and fro-ing of who has the most powerful supercomputer. Currently, it is Japan’s Fugaku supercomputer in Kobe with over seven million cores operating at over 400 petaflops. These numbers don’t mean anything to you or me, but the point is that the world already has some really, really big computers.

At the first Quantum London events, I hosted in 2019 the most common question was “Is a quantum computer just like having a supercomputer or access to a really big cloud computer?”

Essentially the answer is no. For those types of calculations that QCs are suited to they are so much better that it is impossible to imagine the scale of a “classical” supercomputer that would compare. As such it is most useful to think of quantum computers as a completely different way of operating.

How about this for an analogy? Imagine a Chicago-based salesperson whose only equipment is a car. If you give her access to a plane, she can fly. This opens up a whole new set of potential customers but essential she operates in the same face-to-face way. What happened if instead you introduced a telephone. This allows a very different change to her modus operandi, and a more fundamental change to how she operates and the advantage she has over her competition. She may still want to do face-to-face for new clients, but for staying in touch with regular clients she suddenly doesn’t need to travel at all (by car or plane).

In the same way, instead of thinking of quantum computers as “generally better than classical computers” consider them as tools for “doing some tasks far, far, far better than classical computers”.

The question for managers and executives is therefore: “what are these tasks?”.

Time to forget

To repeat ourselves, we do not need to know the physics of what’s going on here. So, if anyone uses the word superposition or entanglement tell them politely but firmly to move to the next slide or make space for someone who can focus on the business questions. Similarly ignore all reference to annealing quantum machines, absolute zero, coherence time, doped diamonds, teleportation protocols, quantum logic gates, or topological qubits. Yes, if and when you and your company start your quantum journey your staff may use these phrases and you’ll slowly learn, but no salesperson, consultant or quantum guru you engage with over the coming months should be wasting a second of your time referring to these.

The briefest of histories

While it is absolutely not necessary to know anything about the history of quantum computers, here’s a sixty second summary in case you’re interested.

Quantum physics started being discussed at the start of the 20th century, and in fact 2021 marks the centenary of Albert Einstein’s Nobel Prize for his work proposing the photon as a quantum of light which behaves like a particle. The use of these quantum mechanical concepts in computers was first theorised in the 1980s by British physicist David Deutsch, with conceptual work on algorithms progressing far faster than any hardware that could run the algorithms. In the 1990s and early 2000s the first efforts to build the hardware started and progressed slowly from a qubits point of view, with massive new knowledge being developed.

What started as pure academic research spun out into deep-tech start-ups and the commercially focused labs of large tech players. This accelerated matters and in the 2010s machines usable for research were being built by a growing number of firms. As timelines for moving to commercially relevant machines became clearer there has been a rapid growth in companies identifying the practical applications of the technology, creating a symbiotic relationship with the hardware manufacturers. In the last five years, the engagement of big-name end customers and increasing numbers of venture capital firms has continued the acceleration.

NISQ

In the next section, we will get into detail about the specific types of problems that QC appears best at solving. Before that, though there is one buzzword we do need to talk about.

For the next few years at least, one term you should be aware of is NISQ. This stands for Noisy Intermediate Scale Quantum. It was coined by leading quantum thinker John Preskill in 2017 to describe this early stage of technical development. This is the point where engineers can get basic QC working but remain such “amateurs” when it comes to controlling them that the amount of ‘noise’ means there is not a whole load we can do. ‘Noise’ in this case does not refer to audible sound but rather various types of interference that cause errors. The world is in the NISQ era and will remain in this state for the next few years at least. This is a necessary step.

A parallel might be the early days of flying. Pioneers like the Wright brothers had understood that if you created wings of a certain shape and accelerated the plane enough you could have heavier-than-air flight. The first few years were experiments of no ‘practical use’. Though the planes lifted higher and traveled an increasing distance, these were still only experiments with no commercial value created. However, they were an entirely necessary step. One can consider the current NISQ era the same for quantum computers. And much as the pioneers of flight were confident that with time they would develop more control, the pioneers of QC are certain that in just a few years more sophisticated hardware and improved error correction will mean that they can deliver solutions with genuine value.

What does a quantum computer look like?

By now you may have seen the funky-looking spider’s web of gold that accompanies most articles discussing quantum computing. This complexity is the inside of the machine, much like if you open your laptop or iPhone you see complexity. For reasons lost in time people thought it was worth making the devices look as exciting as their potential, and so that’s why they all look so funky.

IBM in fact went a stage further in 2019 when they asked the same company that had designed the display cases for the British Crown Jewels to develop a casing for the IBM System Q One. The result was an extraordinarily impactful and beautiful representation of a design-led technology future.

It should be noted that the images of a gold spiders’ web you are regularly seeing are typically of a superconducting quantum computer, where most of what is visible is the cooling and control units to keep the device at around 15 millikelvins, not far above (buzzword alert!) absolute zero and 100 times colder than Space. These are typically about the height of a human and weigh a few 100kgs

The actual quantum chip with the ‘qubits’ in sits at the bottom of the contraption and is a gold-plated copper disc a few centimeters across that holds a wafer of silicon.

How do you get yourself a QC?

The players

Many companies are developing quantum computers — these range from traditional large tech firms, scale-ups who have been working on the topic since the early 2000s, and new start-ups just a few years old.

In most cases, no one will buy a whole quantum computer. Rather they will connect to one via the cloud and use its capacity when they need it. This concept of “QCaaS” — Quantum Computing as a Service — will make for a far faster uptake of the technology compared to where a billion-dollar bet would be required to buy a machine.

Some organisations — e.g., governments, universities, and very heavy corporate users — will buy their own device for cost and security reasons, but as at early 2021 only a handful of machines have been bought. IBM has sold one to the German government and another to a Japanese university/research institution. In March 2021 the Cleveland Clinic made headlines as the first private-sector, on-premise installation of an IBM Quantum System One in the US. In the UK there are no commercially usable quantum computers, though this will change soon as Rigetti is currently building one for the UK Government just outside Oxford, with the initial machine ready by the end of 2021.

The hardware development space is rapidly moving so a comprehensive list will immediately be out of date. As and when you start your quantum readiness journey your experts will consider which type of hardware and which provider(s) it makes most sense to engage with. High-profile names in the hardware space include IBM, Google, Honeywell, Rigetti, D-Wave, IonQ, Oxford Quantum Circuits and PsiQuantum. Many of the start-ups/scale-ups have received hundreds of millions of investment from leading investors including Goldman Sachs, Andreessen Horowitz and Y-Combinator.

Which one do I pick?

It is also worth being fleetingly aware that there are different types of underlying technology being used. The names and physical differences are not important. The only ‘game changer’ will be if a manufacturer can identify how to deliver several orders of magnitude more qubits than their competition. If you look inside any classical computer or smartphone the underlying microchip technology is very standardised. Quantum Computing is far, far from that level of standardisation.

If you’ve paid attention to your digital disruption history, you will of course ask if there a “VHS vs Betamax” dilemma. The answer for the vast majority of potential users is ‘no’. That is because they can ignore the underlying hardware as companies developing the algorithms and software are ensuring that they can work on multiple manufacturers’ hardware, and in many cases on fundamentally different quantum computing technologies.

It is very likely that as the sophistication evolves over the next decade different types of hardware will prove to be more suited for solving specific types of problems. We are some way from that currently, and this uncertainty need not be a barrier for companies as you think about how to become quantum ready.

Accessing a QC

As mentioned, most companies will access quantum computing power by linking to the manufacturers’ machines remotely (‘via the Cloud’). As your company moves forward in the quantum computing space your teams will rapidly understand the best options, and where external help is needed there is a growing number of specialist consulting firms offering a range of services designed to make it as easy as possible to access the power of nascent quantum machines.

Quantum advantage, Quantum supremacy and hybrid quantum

A high-profile near-term aim of the QC community is to demonstrate first quantum advantage and then quantum supremacy.

Quantum advantage is a vague term used to reference when a quantum computer can do a task significantly fast than a classical computer.

Quantum supremacy is more clearly defined, with it being the point at which a quantum computer can do a task that is not feasible with a classical computer within any sensible time period. Recent claims of quantum supremacy have been made by Google and by a team of university scientists from Hefei in China. Both claims revolved around having solved a problem billions or trillions of times faster than a supercomputer could. While they are likely true in the purest sense, they were solving esoteric problems with no business value and are essentially a PR exercise. (Some commentators in fact see it as negative PR for the overall sector as it grabs the attention of non-technical business people but is so unrelatable that this audience rapidly loses interest and wonders if the whole topic is irrelevant.)

During this NISQ period where the number of usable qubits will be measured in 100s most of the applications they can be used for give us neither quantum advantage nor quantum supremacy. Of more immediate relevance to business people is the growing field of hybrid quantum.

Hybrid quantum is a natural steppingstone on a quantum journey where those parts of a calculation suited to a quantum computer use a quantum simulator on a supercomputer (HPC). This forces the team working on the problem to understand which computations are QC-relevant and gives them practice in packaging them up in a manner suited to quantum computation. As and when suitable quantum computers become available it is a simple matter of moving those calculations from the quantum simulator to the actual quantum computer.

Scaling: As mentioned earlier, not all qubits are created equally. What matters is not the number but the ‘usable ones’, sometimes referred to as error-free qubits. The aim is to scale these into the hundreds, then thousands and ultimately millions. This scaling is the technical challenge facing scientists and engineers but because each additional error-free qubit doubles the computational power of the device it is a situation where marginal gains are well worth pursuing. The speed of this ‘qubit-growth’ is important to you and your quantum readiness timeline. How the engineers actually do it is not something you need to understand.

Cost and energy use

Two questions that regularly come up in the expert Q&A on Quantum London webinars relate to the cost and the energy usage.

Cost. While no one has a clear sense of the cost of QCaaS (Quantum Computing as a Service) the consensus seems to be that it will be expensive at first but costs will rapidly reduce to the point that they are not a decisive factor in deciding to do quantum computation. While the billions that have been spent on R&D will need to be recouped, the expectation is there will be enough competition in the hardware space to keep pricing manageable. Given the service-based nature of the offering, there may be much to be learned in terms of how the AWS, Microsoft Azure, Google Cloud battle has played out over the past half-decade.

Energy usage. There is significant focus on the electricity usage of ICT equipment currently, and appropriate so, given it uses 5–10% of the world’s energy. However, despite the cooling required for most quantum processing units the overall energy requirement is tiny, and certainly the energy required to solve problems via quantum computer will be less than that required to solve the same problem on a vast supercomputer.

How do you program a quantum computer?

Despite the mind-blowingly complicated technology to build quantum computers, the programming approach for a business user is not equally complicated. Thanks to the interfaces and ‘libraries’ developed by the hardware manufacturers and third parties the end-user in the business has a development environment not much different to what they would use for any other computing system.

Thus, the business users can focus their minds on disaggregating their business problems into those parts that will and won’t benefit from quantum and focus on developing the combined algorithms. In late 2020 Quantum London launched a Coding Community for those who wanted experience of directly coding quantum computers. The users found the process to be not significantly different to the coding they had done on non-quantum machines.

Hybrid technology stack — image created by the author

Even within the world of QC-suited problems there are easier and harder problems, as the articulation of the problem and developing an algorithm varies in complexity. This is the same as in the classical computing world where some of the work of your data analysts is more complex than other pieces.

The ‘difficulty’ of developing the right algorithm is entirely independent of the time to actually run it on a quantum machine. E.g., factoring a larger number into its component primes is a straightforward algorithm that was identified theoretically several decades ago. Optimising variations of the traveling salesperson problem is relatively harder.

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Thank you for reading this section. Continue via the links below or read the ebook (US & International link, UK link)

1. Introduction (this post)
2. Why QC is useful and potential business applications (link to be added)
3. Why busy executives should engage with the topic (link to be added )