Despite the rapid evolution of technology over the last few decades, you may be surprised to learn that the computers we use today are not so different from the first computer built back in 1941. Your computer, while much smaller and faster than its 30-ton predecessors, performs fundamentally the same task: changing and interpreting binary code into a computational result.^{1} Binary code is composed of “bits,” which are the smallest unit of computer data and are represented as either zero or one. Whatever task your computer performs, it does so by processing a series of zeros and ones through an algorithm, which produces a new set of zeros and ones. While traditional computing works for now, we are fast approaching a point where the transistors (memories) of computers will soon be as small as atoms.^{2} If computers are to continue to become smaller and more powerful over time as they have been, new methods of computing will need to be developed. That’s where quantum computing comes in.

## What is Quantum Computing?

It may sound like something out of science fiction, but quantum computing is a reality today. In essence, quantum computing is the application of quantum mechanics to information processing.^{3} Where a traditional computer uses bits, a quantum computer uses quantum bits, or qubits. Just like bits, qubits encode zeros and ones; however, using the power of quantum physics, qubits can be zero, one, or both at the same time.^{4} This might be difficult to conceptualize in a world dictated by classical physics, but the world of quantum physics, which deals specifically with things on the atomic scale, opens up more possibilities. Qubits are able to behave this way due to the phenomena of superposition and entanglement.

Superposition refers to a quantum system’s ability to be in multiple states at the same time, meaning that it can be both “up” and “down”, “here” and “there” simultaneously.^{5} Entanglement refers to a powerful correlation between two quantum particles that is so strong that even when they are far apart, they remain perfectly in unison. Due to superposition and entanglement, quantum computers are able to process an incredible number of calculations at the same time. While a traditional computer is slowed down by the limitations of only working with ones and ones, because a quantum computer can also work with superpositions of ones and zeros, calculations that were considered impossible can now be efficiently completed by a quantum computer, all while expending much less energy. This is why quantum computing is so important for the future of technology. As computer processors get smaller and smaller while the amount of information they compute must get bigger and bigger, eventually, they will reach a stalemate. Because quantum computers can calculate at a much quicker rate, they show promise in addressing this problem.

## History of Quantum Computing

The idea of quantum computing was first introduced in 1982 by Richard Feynman, a physicist and Nobel Prize winner.^{6} During this time, physicists and computer scientists were exploring the concept of a computer based on quantum mechanics, but it was Feynman who ultimately first presented an abstract model that demonstrated how a quantum theory may be applied to a computation system. This meant that a physicist could carry out quantum physics experiments through a computer. In 1985, physicist David Deutsch built upon Feynman’s model and published a paper to introduce the concept of a quantum computer that could be used outside the world of physics; namely, a replacement for traditional computers.^{7} After publication, there was a lot of buzz around this concept, and many possible applications for a quantum computer were brainstormed. However, none of the concepts really took off until 1994, when Peter Shor created a method of solving an infamous problem in number theory called factorization using a quantum computer. This brought to light how one could use mathematical operations to factor large numbers at much more quicker pace than the traditional computer. This sparked interest in quantum computers outside of the scientific community.

Throughout the 20 years since the publication of this paper, significant advancements have been made in the field of quantum computing. Most significantly, the first functional quantum computer was built in 2007 by D-Wave Systems.^{8} Their initial model at this time was 28-qubits. Since that time, they have doubled the number of qubits in their models every year, and in January of this year, they released the first commercially available quantum computer, composed of 2000-qubits.^{9}

## Next Steps and Obstacles

While quantum computing shows promise to revolutionize computers as we know them, there are several obstacles in the way of their widespread commercialization. First of all, in order to program a quantum computer, one must have extensive knowledge of quantum physics. D-Wave is working on this issue with the introduction of new software called Qbsolv, which is set to allow developers to program quantum computers without knowledge of quantum physics.^{10} Of course, the issue is, there are so few quantum computers in this world, that there is little opportunity to develop the necessary skills to program quantum computers. While there are simulators that you can download onto your computer that allow you to test out the D-Wave software, it is not quite the same as running it on a real quantum computer.

Additionally, quantum computing may be more susceptible to errors than traditional computing. Qubits can be affected by a variety of factors, such as heat, noise, and electromagnetism.^{11} While IBM is currently researching a promising solution to detecting errors, this is only one problem facing quantum computing. Another is the issue of coherence.^{12} Coherence is a metric by which the quality of a qubit is measured, which means how long it maintains its quantum properties. Qubits must maintain these properties for an extended period of time for the quantum computer to function, so the next steps for many researchers will be to enhance the coherence of qubits.

## Military Applications

The worlds of defense and intelligence have long been interested in quantum computing. One of the most important things quantum computing has to offer the military is the speed and types of calculations that can be performed by quantum computers.^{13} Given the ability of quantum computers to process data at a much quicker pace than traditional computers, processes that require sifting through large amounts of data could be streamlined using quantum computing. This would allow the military to be much more efficient, optimizing defense logistics such as which way to travel. Additionally, as software becomes more and more integral to operating many weapons, any type of technology that makes this process more efficient and effective is appealing.^{14}

Additionally, this technology has major implications for decrypting communications.^{15} Currently, encryption is dependent on the inability of hackers to solve long encryption keys. However, with quantum computing, a process that would be impossible before could be done within minutes. Therefore, there is currently a race between nations to develop the research necessary to have a leg up on spies and hackers with quantum computing.^{16} Whoever establishes this technology first will have a large strategic advantage. They will be able to develop encryption methods that render them “unhackable.” Currently, the U.S. Army, Navy, and Air Force are working together to establish a quantum communication network.

## Commercial Applications

As stated above, the first commercially available quantum computer was released earlier this year by D-Wave Systems. Other companies working on producing Quantum computers include 1QBit, Optalysys, Quantum Biosystems, and MagiQ.^{17} Though only D-Wave has a commercially available quantum computer at the moment, it is safe to wager that with time, quantum computers will saturate the market. Beyond computers, there are other commercial applications for quantum computing that are on the horizon. Essentially any optimization problem, meaning when you are trying to find the best possible option within your parameters, can be aided by quantum computing.^{18} For consumers, this means that features that would be too complicated for a traditional computer to handle could be available within the next few decades. Most intriguing to many consumers will probably be the way this science will change their smartphones. On a smaller scale, quantum computing is set to optimize the apps on our phones that tell us the weather and the best route to take to work, as your device will be better able to analyze data.^{19} Additionally, the encrypted communication methods the military discovers will likely create the most secure methods with which to communicate and perform transactions over the internet, transforming the financial services industry. Additionally, quantum computing is set to enhance machine learning to a whole new level, meaning that soon, our computers could identify what is in an image, learn more about your habits as an individual, and even develop intuition.^{20} On top of all this, quantum computing sets to transform research as we know it by enabling scientists to process data at lightning speed.^{21} If this proves true, the possibilities for new medical advancements and technological developments are endless.

For now, quantum computing remains accessible to only a small number of people on earth. Yet if the true potential of this science is harnessed, in the future, quantum computing could be behind every major technological advancement. And given how quickly D-Waves managed to make this theory become a reality, that future could be sooner than we think.

## Further Information

Want to learn more about quantum computing? Check out the links below.

Quantum Computing – Stanford Encyclopedia of Philosophy

How Does a Quantum Computer Work? – Veritasium

How to Fight a War With a Quantum Computer – The National Interest

How Quantum Computing Will Change the World – Forbes

How Quantum Computing Could Help Mankind – Bloomberg TV

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