Chinese scientists say they could be a step closer to developing a code-breaking machine, thanks to a recent breakthrough in quantum memory technology.
A quantum computer can crack an encrypted message in hours, but it needs tens of millions of qubits – the quantum information carried by subatomic particles – to make the calculation.
At present, the most powerful quantum computers run with less than 100 qubits, meaning they are limited to simple tasks with little practical value.
However, a team from the University of Science and Technology of China has unveiled a design for a new code-breaking quantum computer using considerably less qubits than it was previously thought were needed.
The team in Anhui province, led by associate professor Zhou Zongquan, published their research on Friday in Acta Physica Sinica, a peer-reviewed journal run by the Chinese Physical Society.
Zhou said in a phone interview on Monday that the team anticipated the computer would still need about 10,000 qubits for the task, but “from an engineering perspective this is much easier to achieve”.
“Our experimental results suggest the idea works,” he said.
Unlike existing quantum computers, which forget a calculation as soon as it is done, this one has a memory.
The memory device is made from a crystal that can store qubits for an hour or so and the idea is that it updates the quantum information as the calculation proceeds.
What is quantum computing and how does it work?
A quantum computer with memory would be able to handle a complex calculation – such as the factoring of large prime numbers for data decryption – using significantly fewer qubits than a computer without memory, according to the paper.
But quantum memory technology is challenging: when the computer tries to read or write information, it triggers atoms in the memory crystal and generates a storm of background noise.
To get around this, Zhou and his team say they have developed a groundbreaking memory control technology that allows them to efficiently separate the fragile qubits from the atomic chaos.
Source: The Star