They are billed as machines that will change the future, but quantum computers themselves are still in the future. All the same, scientists have been working on developing a working quantum computer for years now, and the frenzied competition to be the first has yielded a new record -- a 53-qubit quantum simulator.
Building a quantum computer has gone from a far-off dream of a few university scientists to an immediate goal for some of the world's biggest companies. Tech giants Intel, Microsoft, IBM, and Google are all plowing tens of millions of dollars into quantum computing, which aims to harness quantum mechanics to vastly accelerate computation. Yet the contenders are betting on different technological horses: No one yet knows what type of quantum logic bit, or qubit, will power a practical quantum computer. Google, often considered the field's leader, has signaled its choice: tiny, superconducting circuits. Its group has built a nine-qubit machine and hopes to scale up to 49 within a year--an important threshold. At about 50 qubits, many say a quantum computer could achieve "quantum supremacy" and do something beyond the ken of a classical computer, such as simulating molecular structures in chemistry and materials science, or solving problems in cryptography. Small startup company ionQ, a decided underdog, is sticking with its preferred technology: trapped ions.
Google is leading the pack when it comes to quantum computing. The company is testing a 20-qubit processor – its most powerful quantum chip yet – and is on target to have a working 49-qubit chip by the end of this year. Qubits, or quantum bits, can be a mixture of 0 and 1 at the same time, making them potentially more powerful than classical bits. And if everything goes to plan, the 49-qubit chip will make Google the first to build a quantum computer capable of solving certain problems that are beyond the abilities of ordinary computers. Google set itself this ambitious goal, known as quantum supremacy, in a paper published last July.
Useful quantum computers are one step closer, thanks to the latest demonstration of a technique designed to stop them making mistakes. Quantum computers store information as quantum bits, or qubits. Unlike binary bits, which store a 0 or a 1, qubits can hold a mixture of both states at the same time, boosting their computing potential for certain types of problems. But qubits are fragile – their quantum nature means they can't hold data for long before errors creep in. So researchers wanting to build large-scale computers invented quantum error correction (QEC).
That might not sound like much, but in the quantum computing arms race, several groups are edging past one another as they aim to eventually make a universal quantum computer. A group of researchers at the Joint Quantum Institute has created a quantum simulator using 53 quantum bits, or qubits. Earlier this month, IBM announced a 50-qubit prototype, though its capabilities are unclear. With this 53-qubit device, the researchers have done scientific simulations that don't seem to be possible