From Classical to Quantum. Computing, that Is.
K. Ceres Wright
In 1900, German physicist Max Planck was calculating how the radiation an object emitted was related to its temperature. He came up with a formula that aligned closely with experimental data he was working on. However, the formula only seemed to work if he assumed that the energy of a vibrating molecule was quantized—that is, it could only take on certain values. Using this data, he came up with a formula called Planck’s constant. Other scientists, such as Einstein, Bohr, and Schrodinger, expanded on Planck’s findings and helped develop the field of quantum mechanics.
And taking quantum mechanics one step further segues to quantum computing. But what is quantum computing? Read on below.
What is quantum computing?
Classical computers (PCs, Macs) use bits to store information, either a 1 or a 0. A quantum computer uses quantum bits, often called qubits. They exist in the quantum, or subatomic, realm. Their behavior in this environment allows them to exist in more than one state at the same time, which allows computers to store much more information using a lot less energy.
Quantum computing uses superposition (where any two or more quantum states are added together, resulting in another quantum state) and entanglement (when pairs or groups of particles are linked together no matter how far apart they are).
What can quantum computers do?
One can use quantum computers to look through large amounts of data to find one particular thing, such as one number in a database of 1 million phone numbers. With a classical computer, that would take 1 million steps of looking at each number. But a quantum computer can do the same task in 1,000 steps. A classical computer encodes information into either a 0 or a 1, so a sequence of 30 0s and 1s has about 1 billion possible values. However, a quantum computer can be in a quantum combination of many states, not just either 0 or 1, which is called superposition. This principle allows a quantum computer to perform one billion or more copies of a computation at the same time.
“While the classical computer is very good at calculus, the quantum computer is even better at sorting, finding prime numbers, simulating molecules, and optimization, and thus could open the door to a new computing era,” a recent Morgan Stanley report noted.
Quantum computers can also create communications that cannot be hacked. "In theory, quantum communication can provide an information transmission mode that cannot be cracked or intercepted," said Pan Jianwei, a quantum physicist. "So it will play a significant role in national defense, government affairs, and financial matters, as well as bank transfers and personal privacy," he said.
What are some real-world discoveries?
In August 2017, a team of physicists reported that it sent entangled quantum particles from a satellite, known as Micius, to ground stations that were 1,200 kilometers away. Entangling quantum particles this far apart broke the previous world record, and is a stepping stone to developing unhackable communication networks and, eventually, a space-based quantum internet.
These communications would be unhackable because, due to the principles of quantum mechanics, any attempt by third parties to observe the transmissions will cause the entangled state of the quantum particles to collapse, making it impossible to eavesdrop on the message. A working prototype would have huge implications for cryptography.
In September 2017, China opened a 2,000-km quantum communications line between Beijing and Shanghai. The line is connected to the Micius quantum satellite. Scientists will test the line and troubleshoot it to prevent jams when increasing numbers of people begin to use the line.
What are some companies in the quantum computing industry?
Companies are joining forces to work on developing a quantum computer, and Morgan Stanley projects that the market for quantum computing will be around $5–10 billion a year in the next 10 years, growing at 24.6 percent from 2018 to 2024.
IBM partnered with JPMorgan Chase to apply quantum computing to different aspects of the financial industry such as trading strategies, portfolio optimization, asset pricing, and risk analysis. Samsung is also working with IBM to study use cases on the semiconductor and electronics industry.
Google is getting in on the act, as well. It partnered with NASA and the Universities Space Research Association to set up the Quantum Artificial Intelligence Lab project. The project seeks to use quantum computing to improve NASA’s ability to solve mission-related problems.
Not to be left behind, Microsoft recently announced the launch of the Microsoft Quantum Network—a global community of individuals and organizations working together to advance quantum computing.
As we can see, quantum computing is already a large industry and will only increase over time as more companies enter the arena and find more applications. As the National Review stated: “Let’s make no mistake: The race for a quantum computer is the new arms race."