In 1965, Intel co-founder Gordon Moore observed that the number of transistors per square inch on a chip had doubled every year since their invention while costs were cut in half – a phenomenon known as Moore’s law.
Over 50 years of chip innovation has allowed transistors to get smaller and smaller to the point where it is no longer physically possible to further reduce the size of transistors. As a result, advances in computing are slowing down and new ways of processing information will have to be found if we are to continue to reap the benefits of rapid growth in computing.
Enter quantum computing – a radical new technology that could profoundly impact all of our lives. It has, for example, the potential to transform medicine and revolutionize the fields of artificial intelligence and cybersecurity.
But what exactly is quantum computing and how does it differ from the computers we use today? In short, it is fundamentally different. Computers today operate using bits that are best thought of as tiny switches that can be in the off (zero) position or the on (one) position. Ultimately, all digital data today – whether it’s a website or app you visit or an image you download – comprises millions of bits made up of ones and zeros.
How does quantum computing work?
However, instead of bits, a quantum computer uses something called a qubit. The power of these qubits lies in their ability to scale exponentially, so that a two-qubit machine allows four simultaneous calculations, a three-qubit machine allows eight calculations, and a four-qubit machine performs 16 simultaneous calculations.
According to Wired magazine, the difference between a traditional supercomputer and a quantum computer is best explained by comparing the approaches they might take to get out of a maze. For example, a traditional computer will try each route in turn, ruling out each until it finds the correct one, whereas a quantum computer will take each route at the same time. “He can keep uncertainty in his head,” Wired claims.
Rather than having a clear position, unmeasured quantum states occur in a mixed “superposition”, similar to a coin spinning in the air before landing in your hand.
While a single qubit can’t do much, quantum mechanics has another phenomenon called “entanglement”, which allows qubits to be configured in such a way that their individual probabilities are affected by the other qubits in the system. . For example, a quantum computer with two entangled qubits is a bit like tossing two coins at the same time and while they are in the air, all possible combinations of heads and tails can be represented at once. The more qubits are entangled, the more combinations of information can be represented simultaneously.
Main quantum applications
Building a quantum computer is not without its challenges. Not only does it have to keep an object in a superimposed state long enough to perform various processes on it, the technology is also extremely sensitive to noise and environmental effects. Quantum chips must be kept cooler than outer space to create superpositions and information only stays quantum for so long before it is lost.
Nevertheless, the researchers predicted that quantum computers could help solve certain types of problems, especially those involving an impressive number of variables and potential outcomes, such as simulations or optimization questions. For example, they could be used to improve software for self-driving cars, predict financial markets, or model chemical reactions. Some scientists even think that quantum simulations could help find a breakthrough in the fight against diseases like Alzheimer’s disease.
Cryptography will be a key application. Currently, encryption systems rely on breaking down large numbers into primes, a process called factorization. While this is a slow process for classical computers, for quantum computers it can be done very easily. Therefore, all of our data could be put at risk if a quantum computer fell into the “wrong hands”. However, one way to protect data is to use quantum encryption keys that cannot be copied or hacked.
There is no doubt that quantum computing could be a breakthrough technology. And while the prospect of a quantum laptop or cellphone seems a long way off, it’s likely that quantum computers will be widespread in academia and industry – at least for some applications – within the next three to five years. .