China’s quantum computer named Jiuzhang 3, developed by Pan Jianwei’s team at the University of Science and Technology of China, has reportedly solved a complex mathematical problem in a millionth of a second. This task would take the world’s fastest supercomputer over 20 billion years. The machine uses photons to carry qubits, the basic unit of quantum information and has increased the number of photons used from 76 to 255. Despite this, quantum computers are not yet ready to replace conventional computers due to their need for a protected environment and high error rate.
“In the next five to 10 years, it is possible that we will see the emergence of quantum computers with several hundred qubits, some even with partial error correction capabilities.”
– Peter Zoller, University of Innsbruck
China’s Quantum Computer
The Jiuzhang series, a quantum computing machine developed by a team of researchers led by Pan Jianwei from the University of Science and Technology of China, has made significant strides in quantum computing. The first Jiuzhang machine was built in 2020 and uses photons, tiny particles that travel at the speed of light, as the physical medium for calculations. Each photon carries a qubit, the basic unit of quantum information.
The latest prototype, JiuZhang 3, has reportedly broken the record set by its predecessor with a one million-fold increase in calculation speed. This advancement was achieved by increasing the number of photons from 76 to 113 in the first two versions of the machine to 255 in the latest iteration.
Quantum Computing Speed and Complexity
The research team claims that their latest quantum computer has solved an ultra-complicated mathematical problem within a millionth of a second. This task would take the world’s fastest supercomputer, Frontier, over 20 billion years to complete. The problem was based on Gaussian boson sampling that simulates the behavior of light particles passing through a maze of crystals and mirrors.
While initially proposed as a physical game without purpose, some recent studies suggest that boson sampling could have potential applications in cryptography. The research team stated that Jiuzhang 3 solved a problem with the highest sample complexity, processing the task within one-millionth of a second.
The Race for Quantum Supremacy
Countries like China and the US are in a competitive race to achieve “quantum supremacy”, a point at which a machine can outperform classical computers, solving problems that are beyond the capabilities of conventional machines. Different methods are being used to approach this objective, with photonic processors being just one of several types of quantum computing.
A company based in Toronto, Xanadu, competes with light-based systems. In collaboration with the US National Institute of Standards and Technology (NIST), the firm unveiled its Aurora quantum processor, with 216 photons, in 2022.
Limitations of Current Quantum Computers
Despite their speed, these quantum machines are not about to replace common computers. At this stage, they can only work in a protected environment for short periods on highly specific tasks. They also make a lot of mistakes. In 2021, when Jiuzhang 2 was launched, Pan said the team hoped to achieve quantum error correction within four to five years.
Quantum computing pioneer Peter Zoller stated that a breakthrough in error correction was needed for quantum computers to become truly practical. He speculated that it would require tens of thousands, or even millions of qubits, along with robust error correction capabilities to actualise a large-scale and high-speed quantum computer.
“In 2021, when Jiuzhang 2 was launched, Pan said the team hoped to achieve quantum error correction “with four to five years of hard work”.”
Pan Jianwei, University of Science and Technology of China at Hefei
Future of Quantum Computing
The future of quantum computing looks promising, with the possibility of quantum computers with several hundred qubits, some even with partial error correction capabilities, emerging in the next five to 10 years. However, developing a large-scale and high-speed quantum computer would require robust error correction capabilities and a significant increase in qubits.
“The fastest classical supercomputer Frontier – developed in the US and named the world’s most powerful in mid-2022 – would take over 20 billion years to complete the same task, the researchers said.”
Researchers from the University of Science and Technology of China at Hefei
Summary
China’s latest quantum computer, Jiuzhang 3, has reportedly solved a complex mathematical problem in a millionth of a second, a task that would take the world’s fastest supercomputer over 20 billion years. Despite this, quantum computers are not yet ready to replace conventional computers, as they can only operate in a protected environment for short periods on highly specific tasks and are prone to errors.
“The JiuZhang 3 prototype also smashed the record set by its predecessor in the series, with a one million-fold increase in calculation speed, according to a paper published on Tuesday by the peer-reviewed journal Physical Review Letters.”
Physical Review Letters Journal
- The Jiuzhang 3, a quantum computer developed by a team led by Pan Jianwei from the University of Science and Technology of China, has reportedly solved a complex mathematical problem in a millionth of a second. This is significantly faster than the world’s fastest supercomputer, Frontier, which would take over 20 billion years to complete the same task.
- The Jiuzhang series uses photons as the physical medium for calculations, with each photon carrying a qubit, the basic unit of quantum information. The latest version of the machine uses 255 photons, a significant increase from the 76 and 113 used in the first two versions.
- The problem solved by Jiuzhang 3 is based on Gaussian boson sampling, simulating the behaviour of light particles passing through a maze of crystals and mirrors. This task could potentially have applications in cryptography.
- Other countries, including the US, are also striving to achieve “quantum supremacy”, where a machine can outperform classical computers. Different methods are being used, with photonic processors being one type of quantum computing.
- Despite their speed, quantum computers are not yet ready to replace common computers. They can only work in a protected environment for short periods on highly specific tasks and are prone to errors. Quantum error correction is a significant challenge that needs to be overcome for quantum computers to become truly practical.