Quantum computing explained

Quantum research today means big business. What was once seen as a scientific curiosity, quantum computing now promises to transform many aspects of everyday life from cybersecurity to drug development and weather forecasting. In recent years work in quantum computing has begun to move out of universities and into corporate research labs, with large multinationals as well as start-ups and venture capitalists entering the race to commercialize quantum technologies. But for all the record funding announcements and hype, some warn that this is fostering a “quantum bubble” that may soon pop. 

The heart and soul of a quantum computer are quantum bits, or qubits. These are different from standard computer bits, which can be either 0 or 1. Qubits, on the other hand, can be both. Using this feature for complex computational problems means it could be possible to calculate solutions much faster than today’s fastest computers by scaling computing to calculate with many qubits, resulting in exponential increase in computing power. Qubits can be made from different hardware platforms, such as superconducting qubits or trapped ions. Other upcoming methods are photonic quantum processors that use light instead.

Experts say that a real “quantum advantage” can only be expected when quantum computers operate with a million qubits. And with the current record still below 100 qubits there is still some way to go. But what is mostly hindering progress is the decoherence of the qubits themselves. To avoid this, they usually have to be operated at near 0 K and shielded from each other and the environment. Scientifically, however, there is nothing stopping the creation of large-scale quantum computers, but there are some tough engineering problems to solve.