What is quantum computing and why does the future of Earth depend on it?

Computing power is reaching a crisis point. If we continue to follow the trend in place since computers were introduced, by 2040, we will not have the capability to power all of the world’s machines, unless we can crack quantum computing.

Quantum computers promise faster speeds and more robust security than their classical counterpart, and scientists have been striving to create a quantum computer for decades.

What is quantum and how does it help us?

Quantum computing differs from classical computing in one fundamental way—the way information is stored. Quantum computing makes the most of a strange property of quantum mechanics, called superposition. It means one ‘unit’ can hold much more information than the equivalent found in classical computing.

Information gets stored in ‘bits’ in state ‘1‘ or ‘0,’ like a light switch that turns on or off. By contrast, quantum computing can include a unit of information that can be ‘1,’ ‘0,’ or a superposition of the two states.

Think of a superposition as a sphere. ‘1‘ is written at the north pole, and ‘0‘ is written at the south—two classical bits. However, a quantum bit (or qubit) can be found anywhere between the poles.

“Quantum bits that can be on and off at the same time, provide a revolutionary, high-performance paradigm where information is stored and processed more efficiently,” said Dr. Kuei-Lin Chiu to Alphr in 2017. Dr. Chiu was a researcher for the quantum mechanical behavior of materials at the Massachusetts Institute of Technology.

The ability to store a much higher amount of information in one unit means quantum computing can be faster and more energy-efficient than computers we use today. So why is it so hard to achieve?

Making qubits

Qubits, the backbone of a quantum computer, are tricky to make and, once established, are even harder to control. Scientists must get them to interact in specific ways that would work in a quantum computer.

Researchers have tried using superconducting materials, ions held in ion traps, individual neutral atoms, and molecules of varying complexity to build them. However, making them hold onto quantum information for a long time is proving difficult.

In recent research, scientists at MIT devised a new approach, using a cluster of simple molecules made of just two atoms as qubits.

“We are using ultracold molecules as ‘qubits’” Professor Martin Zwierlein, lead author of the paper, told Alphr in 2017. “Molecules have long been proposed as a carrier of quantum information, with very advantageous properties over other systems like atoms, ions, superconducting qubits, etc. “Here, we show for the first time, that you can store such quantum information for extended periods in a gas of ultracold molecules. Of course, an eventual quantum computer will have to also make calculations, for example, have the qubits interact with each other to realize so-called “gates.” Zwierlein continued, “But first, you need to show that you can even hold on to quantum information, and that’s what we have done.”

The qubits created at MIT held onto the quantum information longer than previous attempts, but still only for one second. This timeframe might sound short, but it is “in fact on the order of a thousand times longer than a comparable experiment that has been done,” explained Zwierlein.

More recently, researchers from the University of New South Wales made a significant breakthrough in the push towards quantum computing. They invented a new type of qubit called a flip-flop qubit, which uses the electron and the nucleus of a phosphorus atom. They are controlled by an electrical signal instead of a magnetic one, making them easier to distribute. The ‘flip-flop’ qubit works by pulling the electron away from the nucleus using an electric field, creating an electric dipole.

Beyond qubits

It is not just qubits, however, that scientists need to figure out. They also need to determine the material to make quantum computing chips successfully.

Chiu’s paper, published earlier in 2017, found ultra-thin layers of materials that could form the basis for a quantum computing chip. Chiu said to Alphr, “The interesting thing about this research is how we choose the right material, find out its unique properties, and use its advantage to build a suitable qubit.”

“Moore’s Law predicts that the density of transistors on silicon chips doubles approximately every 18 months,” Chiu told Alphr. “However, these progressively shrunken transistors will eventually reach a small scale where quantum mechanics play an important role.”

Moore’s Law, which Chiu referred to, is a computing term developed by Intel co-founder Gordon Moore in 1970. It states that the overall processing power for computers doubles about every two years. As Chiu states, the chips’ density decreases—a problem that quantum computing chips can potentially answer.

Is quantum computing the ultimate vaporware?

What is vaporware?

In case you never heard of the term vaporware, it is essentially a software-related product that is advertised but not yet available or possibly never becomes available. An example is a software product that was heavily marketed but never saw the light of day.

Despite people making optimistic predictions for decades about the impact of quantum computers, and the various advancements in business and research environments, how close are we to achieving the dream of quantum computing? Is this situation a prediction of future vaporware, or will it become something of use?

We delve into the reality of quantum computing in another article. In summary, a quantum computer will likely perform a very unrealistic computation faster than a conventional computer in the next year or two. However, it won’t be a straightforward process, and it won’t be cheap or beneficial for everyday consumers.