A team of researchers affiliated with multiple institutions in China,
working at the University of Science and Technology of China, has achieved
another milestone in the development of a usable quantum computer. The group
has written a paper describing its latest efforts and have uploaded it to
the arXiv preprint server.

Back in 2019, a team at Google announced that they had achieved "quantum
supremacy" with their Sycamore machine—a 54 qubit processor that carried out
a calculation that would have taken a traditional computer approximately
10,000 years to complete. But that achievement was soon surpassed by other
teams from Honeywell and a team in China. The team in China used a different
technique, one that involved the use of photonic qubits—but it was also a
one-trick pony. In this new effort, the new team in China, which has been
led by Jian-Wei Pan, who also led the prior team at the University of
Science and Technology has achieved another milestone.

The new effort was conducted with a 2D programable computer called
Zuchongzhi—one equipped to run with 66 qubits. In their demonstration, the
researchers used only 56 of those qubits to tackle a well-known computer
problem—sampling the output distribution of random quantum circuits. The
task requires a variety of computer abilities that involve mathematical
analysis, matrix theory, the complexity of certain computations and
probability theory—a task approximately 100 times more challenging than the
one carried out by Sycamore just two years ago. Prior research has suggested
the task set before the Chinese machine would take a conventional computer
approximately eight years to complete. Zuchongzhi completed the task in less
than an hour and a half. The achievement by the team showed that the
Zuchongzhi machine is capable of tackling more than just one kind of task.
It also showed that adding just two more qubits than that used by Sycamore
could increase the power of a quantum computer exponentially. But perhaps
more importantly, it demonstrates that computer scientists are moving ever
closer to the real prize—the development of a generalized quantum computer
that can be used for a host of real-world applications that traditional
computers will never be able to handle.

## Reference:

Strong quantum computational advantage using a superconducting quantum
processor, arXiv:2106.14734 [quant-ph]
arxiv.org/abs/2106.14734