Earlier this year, Google engineering director Hartmut Neven warned that China's ability to quickly devote massive resources to a single task poses a new technological challenge to the US and other countries.
"We are indeed most worried about an unknown competitor out of China to beat us in the race to such a machine because China as a society just has the ability to steer enormous resources in the directions that are deemed strategically important," Neven told a Centre for Strategic and International Studies event in Washington, DC in January.
Neven said developing quantum computers will bring tremendous advantages to various industries, for example, it could help find the optimal configuration for chemical reactions, increase the accuracy of weather prediction and help governments better predict and fight against cyberthreats.
"In Silicon Valley, we say only the paranoid survive, so there's always a hit list of your biggest worries," Neven said.
Canada, Germany, the UK, France, Russia, Japan and South Korea are also looking into the supercomputers of tomorrow and pouring large sums of money into research and development.
Google said last year it had built a computer - named Sycamore - that could perform a computation in 200 seconds that would take the fastest supercomputers about 10,000 years, reaching quantum supremacy.
That claim was disputed by IBM. Google said it had chosen a random number generating problem which was difficult and prohibitively time-consuming for a classical machine. But in a technical paper and blog post IBM has shown that it is possible on a normal computer if it has enough storage.
The company's own supercomputer - named Summit - solved it in just two-and-half days. Although that is vastly slower than the 200 seconds achieved by Sycamore, if true, it would still prevent Google claiming to have made a literal "quantum leap".
The Chinese researchers claim their new prototype is able to process 10 billion times faster than Google's prototype, according to the Xinhua report.
Xi Jinping's government is building a US$10 billion National Laboratory for Quantum Information Sciences as part of a big push in the field.
In the US, the Trump administration provided US$1 billion in funding to research into artificial intelligence and quantum information earlier this year and has sought to take credit for Google's 2019 breakthrough.
What is quantum computing?
Quantum computing is based on quantum bits or qubits. Unlike traditional computers, in which bits must have a value of either zero or one, a qubit can represent a zero, a one, or both values simultaneously.
Representing information in qubits allows the information to be processed in ways that have no equivalent in classical computing, taking advantage of phenomena such as quantum tunneling and quantum entanglement.
As such, quantum computers may theoretically be able to solve certain problems in a few days that would take millions of years on a classical computer. (Source: Nasa)
The key players
Microsoft
Chief executive Satya Nadella has named quantum computing as one of the three technologies that his company will focus its R&D efforts on (along with augmented reality and artificial intelligence)
IBM
The veteran technology company has dedicated part of its business to the development of hardware and software for quantum computers, led out of Zurich.
Google
The Alphabet-owned search business was late to the game, but has partnered with Nasa and the US Universities Space Research Association to speed up production for a quantum computer that can beat any supercomputer in 2019.
Intel
The world's largest chipmaker has invested in silicon-based quantum computing, a challenging but potentially rewarding technology that could leapfrog the likes of Google, Microsoft and Intel if it manages to scale faster than semiconductor technology.
Alibaba
The Chinese technology giant has pledged to deliver a quantum chip in the next two years. The company, which entered the cloud quantum space last year, is also developing quantum processors.
