Monday, May 20, 2024

China demonstrates the world’s most powerful quantum computer

A team of engineers from the China University of Science and Technology has demonstrated what they believe to be the world’s most powerful quantum computer. The team says their quantum computer completed a calculation in just over an hour that would take the world’s most powerful classical supercomputer eight years to crack.

This is the latest global milestone in a series of fascinating quantum computing advancements over the past two years. During this period, researchers across the world finally reached the long-sought-after ‘quantum supremacy’ – the point at which quantum computing can solve a problem that would take an impractical time for classical computing.

According to the researcher Jian-Wei Pan and his colleagues, their quantum computer has broken the previous record by Google. Back in 2019, Google announced that its 54-qubit Sycamore processor was the first to achieve quantum supremacy. Sycamore completed a calculation in 200 seconds that would have taken 10,000 years on the world’s most powerful supercomputer.

In fact, it is not the first time that China has beaten the rest of the world in quantum computing. It had already surpassed Google’s record in 2020 – achieved with superconducting qubits – with a machine that used photonic qubits. But that computer was experimental and not programmable. The Jian-Wei Pan team’s machine uses superconducting qubits on a quantum processor called Zuchongzhi.

Zuchongzhi is a two-dimensional programmable superconducting quantum processor that can simultaneously manipulate up to 66 functional qubits. Engineers used 56 of them to tackle a computational problem designed to test the computer’s prowess.

“We estimate that the sampling task finished by Zuchongzhi in about 1.2 hours will take the most powerful supercomputer at least eight years,” engineers wrote in the paper. “The computational cost of the classical simulation of this task is estimated to be 2-3 orders of magnitude higher than the previous work on 53-qubit Sycamore processor.”

According to the team, the problem the computer was solving was around 100 times more challenging than the one solved by Google’s Sycamore processor in 2019. While Sycamore used 54 qubits, Zuchongzhi used 56, showing that by increasing the number of qubits, a processor’s performance will improve exponentially.

“Our work establishes an unambiguous quantum computational advantage that is infeasible for classical computation in a reasonable amount of time. The high-precision and programmable quantum computing platform opens a new door to explore novel many-body phenomena and implement complex quantum algorithms.”