Quantum Computing: Beyond Zeros and Ones

Tianhe-2 is the one of the world’s fastest supercomputers. Its 3.2 million Intel cores, which takes up space roughly equivalent to half a football field, are capable of processing 34 quadrillion calculations per second.

But the future of computing could fit into a traditional computer rack, or perhaps an even smaller box, kept at temperatures colder than interstellar space. While nowhere near as powerful as Tianhe-2—yet—the idea of quantum computing has scientists abuzz, and for good reason.

Quantum computing, an emerging area of technology, offers incredible applications for science, medicine, government, and financial services—even if it is still largely at a theoretical stage. It is not hyperbole to say that risk management at the very least could be transformed at a fundamental level by the technology, which also presents enormous challenges for an industry that may not be ready to deal with such a meteoric step forward in our technological capabilities as a species.

“Even diplomatic missions and military secrets will have to be dealt with in a different way. There will also be legal implications of quantum computing. Maybe there will be a phase-in [period] which the use of large quantum computers will have to be strictly regulated because of security reasons,” says Giulio Chiribella, an associate professor in the computer science department at Hong Kong University.

Despite this, the promise—and the complexity—of quantum computing demands attention, particularly when companies are starting to turn it into a reality.

Bits versus Qubits

But what exactly is a quantum computer and how does it differ from what is now commonly termed a “classical” computer? Classical computers, Chiribella says, are based on the idea that information can be encoded into bits, which was first explored by scientist Claude E. Shannon. These bits have two states: zero and one, which is how our so-called normal computers read information. One might argue that classical computers can mean many things to different people. Before the computers of today were developed, we had analog computers. They were just different types of machines—analog devices that ran computations. Then along came digital computers, which changed our world to what it is now. “What we’re experiencing now is another revolution. It’s the way ‘thinking machines’ evolve,” says Anthony Scriffignano, senior vice president and chief data scientist at Dun & Bradstreet.

If one believes in Moore’s Law—which governs the semiconductor industry and says that the number of transistors on a chip will double every 18 months, or so—we will at some point hit a barrier when transistors shrink to the size of atoms.

Where a quantum computer differs is in its use of quantum bits—or ‘qubits’—which have more than just the two states of zero and one. A quantum computer is essentially a machine that uses quantum mechanics to control more of these states. These additional states are called quantum superpositions. “You can think of ‘zero’ and ‘one’ as two directions in space. Let’s say ‘up’ and ‘down,’ then the quantum superpositions are all the other directions, like east, west, north and south. A classical computer can only look up and down. A quantum computer is able to look in all the other directions,” says Chiribella.

Quantum computers make use of the ability peculiar to subatomic particles, where they exist in more than one state at one time. With all these extra states, a qubit has the capacity to store tremendous amounts of information in volumes that far outstrip a simple bit. Therefore, this also means it has more room to do more computations.

Things start to get a lot more interesting when qubits are combined. “The space of states grows exponentially faster than the space of states in a classical computer,” Chiribella adds.

To get a little mathematical about it, the state of “n” qubits takes about 2ⁿ classical bits—an exponentially larger number. This means that if you want to simulate a quantum computer using a classical computer, it will take an exponentially larger amount of memory.

“As we increase the number of qubits, it becomes impossible for classical computers to keep up,” Chiribella says. “Richard Feynman, the theoretical physicist, regarded as one of the great minds in the development of quantum mechanics, once said: ‘There is plenty of room at the bottom,’ meaning that there is plenty of room to operate with quantum particles, atoms and molecules. In a quantum computer, the ‘room at the bottom’ is an exponentially bigger space that we can use to do our computations.”

Risk and Reward

This previously unfathomable expansion in raw compute power has tremendous applications in financial services. Michael Brett, CEO of quantum computing specialist QxBranch, says quantum computing will eventually be used to help solve—among other things—optimization problems in portfolio management, risk management, analytics, and customer service. It can also be used to improve machine-learning programs due to its ability to speed up computations by considering a large range of possible outcomes simultaneously rather than in sequence or in parallel. 

He sees one of the primary applications as simulating quantum chemistry, the complex behavioral systems that will impact industries like healthcare and energy. An example of this could be simulating large molecules and new materials, as well as chemical and nuclear reactions.

On a longer timescale, Chiribella adds that the simulation of complex systems could be beyond the domain of physics and chemistry. “The stock market, for example—this is a very complex and hard-to-predict system. Its fluctuations can mean huge gains or huge losses. Having the help of powerful quantum computers can make a big difference there. Here one can imagine that big companies like IBM and Google will play a key role and sell the access to their quantum machines to those who want to solve hard simulation problems or hard optimization problems,” he says.

Brett adds that other applications relevant to near-term commercial adoption will be to assist with optimization and accelerating machine-learning algorithm training. “Quantum computing is going to be useful to a very broad range of industries, including finance, pharma, oil and gas, and logistics,” he says.

Dun & Bradstreet’s Scriffignano has three primary cases in mind, all of which have to do with detection. The first is detecting the “incredibly” small signal that a new business creates when it comes to life all over the world. “Companies become visible when they do things to interact with other companies like seek credit or register a website or tweet something, but each one of those has their own challenges,” Scriffignano says. “For example, are they really who they claim to be, is this another version of an existing company, or is it a company or a person? There are a number of really nasty non-binary problems there and since this is a non-binary environment, that seems appropriate for a new quantum approach.”

The next use-case he sees has to do with the exact opposite of the previous use-case. At what point is a company really out of business? Is it when they declare bankruptcy? Then again, Scriffignano says, that would depend on which level of bankruptcy they’re at. “It’s complicated. So they’re not dead, just different. They may be dying but they’re not dead. When it’s a small company and it’s not public, they don’t have to tell everybody everything. They’re called private companies for a reason,” he says.

The third non-binary problem Dun & Bradstreet is looking at is malfeasance. “The problem with fraud or malfeasance is that the best actors, the ones that are best at it, when they know or suspect they are being observed, the first thing they do is change their behavior. So if we try to model that behavior, we are modeling how we know the best ones are not behaving anymore. It’s called an ‘observer effect’ in physics. When you stick a thermometer into a cup of soup to measure the temperature of the soup, you’re measuring the temperature of the soup and the thermometer; you’ve changed the temperature of the soup. When you look at a fraud system and the actors are aware, they change their behavior,” he says.

Dun & Bradstreet is particularly interested at looking at the actions that are the precursors to some commission of fraud or inappropriate action. “Again, they’re doing something in advance of something they’re about to do that will be binary—clearly fraud—but it’s not fraud when they do these things we’re observing. Those are the three places where we think this quantum approach has some chops in the short term,” he says.

The Red Queen

For lessons in the limitations of modern computing, technologists might want to put down the academic papers, and instead pick up a copy of Through the Looking-Glass, and What Alice Found There. In one of the novel’s famous scenes, Alice is constantly running, but remains in the same spot. She then remarks to the Red Queen that in her country, one would get somewhere else if they run very fast for a long time. The Red Queen replies: “Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that!”

The author, Lewis Carroll, was not only a writer but also a mathematician and a logician. He is well-known for secretly slotting mathematical or algebraic lessons into his literary work, and in this case, the “Red Queen” problem has real applications to computing theory and one of its problems: we can only go as fast as we can.

Quantum computing could solve this by unlocking capacities we never knew we had. While the idea of quantum technology has existed for many years, spurred on by a theory that Feynman developed regarding a computer using the effects of quantum mechanics, the theory is starting to become a reality. “We’ve been on this journey, moving from when we didn’t have quantum technology to when we knew it was coming, to when we could simulate the behavior of one to some extent within certain limitations using lots of memory,” says Scriffignano. “Now we are at this cusp where we have one but it’s really ‘small.’ Even really small, it is really big because it is little buckets of infinity—they are qubits, and they are essentially infinitely big, at least in one dimension. They can store an infinite number of values in a finite number of places,” he continues.

Quantum computing is now at the stage where the development emphasis has transitioned from research labs in universities, to commercial research and development. The major actors behind quantum hardware development include Google, Microsoft and IBM, as well as credible, well-funded startups. “There is no broad-scale commercial adoption yet, but we forecast this will happen within about 5 to 10 years,” says QxBranch’s Brett.

IBM has, like many other companies, been on this quantum journey. Only a couple of months ago, it unveiled its prize jewel: a 16-qubit quantum computer for public use and a 17-qubit prototype commercial processor. This is quite an accomplishment from the 5-qubit processor it built only a year ago. It now offers the Quantum Experience via IBM Q, which is available to academics, scientists, developers and anyone looking to experiment with a quantum computer.

Google is rivaling IBM’s achievements and is currently testing a 20-qubit processor, according to international science magazine New Scientist. Google aims to be able to have a 49-qubit chip by the end of this year. If it succeeds, it will be the first to build a quantum computer that can solve certain problems that ordinary computers are simply unable to do.

QxBranch recently delivered a quantum simulator to the Commonwealth Bank of Australia (CBA). The simulator is operational on CBA’s premises, accessible via the bank’s cloud, and provides developers at CBA the chance to experiment, explore and validate applications that are and could be of interest to them, without being tied down by hardware.

The simulator is modeled on the hardware being developed by the University of New South Wales in Australia. David Whiteing, chief information officer at CBA, noted in a statement announcing the project that getting involved now allows the bank to avoid getting stuck at conceptual contemplation. “More and more of what we do with emerging technology is about diving into the field and participating earlier in the process so we can build our understanding of what we need to do to make the most of this technology,” he said.

QxBranch said the simulator emulates the functions of future universal quantum computers, enabling software and algorithm development to proceed in parallel with hardware development.

While this hardware is not available yet, QxBranch’s Brett believes that in the future, quantum computing will be delivered via the cloud, similar to how the company delivered the quantum simulator to CBA.

“The way to think about quantum computers is as an additional high-performance computing service that will be available through the cloud, much as graphics processing units (GPUs) are used today as special-purpose tools. Quantum computers will be another high-performance tool in the global computing toolkit,” he says.

Cool Runnings

Any implementation of a quantum computing infrastructure also faces more prosaic concerns—the extreme heat that would be generated by such a sophisticated and high-performing system, and for maintaining its quantum state. For example, the D-Wave quantum computer is run at 0.015 Kelvin, or -459.6 Fahrenheit, according to the company. This is not necessarily to keep the processor from overheating when it runs, but more to protect the qubits from thermal fluctuations. In digital computers, the zeros and ones of bits are quite stable, but quantum superpositions can easily be destroyed by “noise,” according to Chiribella. “Every attempt to implement a quantum algorithm is an epic fight against noise,” he says.

When the quantum superposition is destroyed, it will result in calculation errors. To run an algorithm, qubits will need to start in their low-temperature ground states. Like any regular computer, a quantum computer will heat up when it is doing the processing work. However, unlike classical computers, a built-in fan will just not be enough for quantum computers to keep cool. Scriffignano says the processing power is also reaching certain theoretical limits where the amount of cooling needed is overwhelmed by the amount of heat generated. “There are all these physical limitations; essentially, we’re getting really close to making things as fast as we can,” he says.

Efforts to address these hurdles are already underway. According to the New Scientist, a team of researchers at Aalto University in Finland, led by Mikko Mottonen, has built the first standalone cooling device for a quantum circuit. This device could be integrated into many quantum electronic devices, including a computer.

The Price of Progress

Such advances are rarely without a cost. A real and fully controllable quantum computer is one that may also be dangerous. This is because of Shor’s algorithm, a quantum algorithm that finds the prime factors of large numbers in an exponentially faster way than any existing algorithm. This algorithm, if unlocked, will render all current security measures that guard credit cards, emails, and, basically, any protected personal data, useless.

This mathematical problem is hard to solve using a classical computer. But with a quantum computer with full control over qubits in the thousands, the problem will be easily solved.

“Removing computational complexity, or at least transforming it as I have described, allows you to do amazing things, but also allows you to unlock the combination lock even when the combination keeps changing the way it does today,” says Chiribella.

In the long term, quantum algorithms like Shor’s will force us to change the way emails are sent, how we conduct e-commerce and organize online databases, anything where security and privacy are of importance, he continues.

“One reaction is to say ‘uh-oh,’” Scriffignano says. “What I hope and suspect is happening is the smartest people in the right organizations are already figuring out how they can counter quantum hacking. Just like you can hack in a quantum way, you can counter hack that way.”

However, many believe this is a natural consequence of development, and advancing our understanding of technology should not be abandoned due to concerns about possible outcomes,” Scriffignano says. “What happens if we don’t move on? That’s exactly the way we have traditionally made revolutionary progress in computer science. What’s the way to store memory after you turn the power off? That was a big problem at one point. What happens if the amount of memory that you have is more than the [address-able] space of the CPU you’re using to process it? That was an insurmountable problem at one point. What happens if there’s more than one CPU? These are all moments, and there were many more of them, when somebody refused to accept the status quo. Quantum computing is an example of that where they basically said, what if the fundamental unit is not a zero or one, but anything between zero and one? That changes everything,” Scriffignano says.

Changes 

The heat is on among those in the race to achieve quantum supremacy. Whoever the winner may be, quantum computing will change not only our businesses but also our lives as we know it. Chiribella puts it in such a way that quantum computing is a “heroic quest to gain control over the microscopic world.”

“It takes both a fundamental understanding of nature and a superior technology to drive quantum particles, like atoms and photons, to do exactly what we want,” he adds. “Realizing quantum computing will surely give us access to a huge potential, but first of all it will be a great human conquest, like the Moon landings or the exploration of outer space.”

Man has always looked to conquer new worlds. This world just happens to be one of ones and zeros.