China has built the world's first photon quantum computer, the computing speed of which could surpass the current most powerful supercomputer by 2020, according to scientists.

The photon computer is about 10 to 100 times faster than the world's first electronic and transistor computers, and 24,000 times faster than similar experiments on photon quantum computing, said Pan Jianwei, an academician at the Chinese Academy of Sciences, which has built the machine.

The current model only uses five qubits — a unit of quantum information — so its calculation speed is still slower than a modern cellphone.

However, with 20 qubits, which will be achieved this year, its speed will surpass the fastest laptop on the market, and with 50, it could surpass the fastest supercomputer by 2020, and at a fraction of the energy cost, Pan said.

"Quantum computers could solve problems that have septillions (1 followed by 24 zeros) of variables in a matter of seconds, while even today's most powerful supercomputer would take centuries," he said. "It will analyze and simulate weather forecasts, medicine, commerce and other data intensive fields at an unprecedented speed and scale."

He added that his team will make its photon quantum computer platform available for public use by year's end.