By Michael Irving

Researchers in China claim to have achieved quantum supremacy, the point where a quantum computer completes a task that would be virtually impossible for a classical computer to perform. The device, named Jiuzhang, reportedly conducted a calculation in 200 seconds that would take a regular supercomputer a staggering 2.5 billion years to complete.

Traditional computers process data as binary bits – either a zero or a one. Quantum computers, on the other hand, have a distinct advantage in that their bits can also be both a one and a zero at the same time. That raises the potential processing power exponentially, as two quantum bits (qubits) can be in four possible states, three qubits can be in eight states, and so on.

That means quantum computers can explore many possibilities simultaneously, while a classical computer would have to run through each option one after the other. Progress so far has seen quantum computers perform calculations much faster than traditional ones, but their ultimate test would be when they can do things that classical computers simply can’t. And that milestone has been dubbed “quantum supremacy.”

by Bob Yirka

A team of researchers affiliated with several institutions in China has built and tested a photonic quantum computer that demonstrates quantum supremacy. In their paper published in the journal Science, the group describes their computer, which they call Jiuzhang, and how well it performed while conducting Gaussian boson sampling.

Quantum computers have been in the news lately as scientists try to determine if they can meet expectations.

Quantum computers could vastly outperform conventional machines on certain tasks. The goal is to achieve what has come to be known as” quantum supremacy”—where a quantum computer can outperform conventional computers on at least one type of task.

Until now, only one computer has ever achieved this feat—Google’s Sycamore device. And because the field is still so new, researchers around the world are working on vastly different designs. Sycamore was based on qubits represented by superconducting materials. In this new effort, the team in China has developed a photon-based quantum computer capable of carrying out a single specific type of calculation—boson sampling.