Scientists encouraged to make more original innovations, breakthroughs

President Xi Jinping has stressed that China will advance the development of quantum science and technology with more strategic planning, supportive policies and investment, with the aim of fostering a favorable environment for basic research, innovation, talent training and commercialization in this field.

During a group study session of the Political Bureau of the Communist Party of China Central Committee held on Friday, Xi, who is also general secretary of the CPC Central Committee and chairman of the Central Military Commission, said quantum science and technology is at the forefront of a new round of sci-tech and industrial revolutions.

As a result, developing quantum science and technology is of great scientific and strategic significance, he said.

China's scientific and technological workers have made great efforts to catch up in quantum science and technology and have made a number of significant innovations with international influence. On the whole, China possesses strength in terms of science and technology and innovative abilities in this field, Xi said.

However, China's quantum science and technology development still has many weak links and faces multiple challenges, he said, calling for efforts to follow the path of independent innovation, make breakthroughs in key core technologies, ensure the safety of industrial and supply chains and enhance the ability to respond to international risks and challenges.

It is imperative to systematically sum up the successful experience of China's quantum science and technology development, learn from the useful practices of other countries, thoroughly analyze and judge the development trends, and find the breakthrough point for the development of quantum science and technology in China, Xi said.

He advocated more strategic planning, policy support and investment in quantum science and technology. Training more quality talents, granting scientists more resources and autonomy and enhancing international cooperation are also important for the development of this field, he added.

Quantum science and technology is the study and application of the physical properties of matter at the scale of atoms and particles. The foundational theory of quantum physics is quantum mechanics, and the current three major applications of quantum physics are quantum communication, quantum computing and quantum precision measurement.

For decades, scientists have believed that harnessing the bizarre phenomena of quantum mechanics could lead to ultra-secure communication for political, economic and military use.

It can also lead to the creation of ultrapowerful computers that can simulate extremely complex models, allowing new discoveries in fields ranging from medicine to material sciences, as well as greatly improving the accuracy of weather and financial forecasting and the efficiency of machine learning and artificial intelligence.

Chen Yu'ao, a quantum physics professor at the University of Science and Technology of China, said he was greatly encouraged by Xi's speech, which showcased that China is attaching immense significance to this cutting-edge field which is critical for promoting high-quality development and safeguarding national security.

"We are also excited to see support for industrializing and commercializing our basic research into new applications," Chen said.

Zhang Qiang, a professor of quantum communication at USTC, said apart from excitement, he also felt the urgency to develop quantum science and technology.

"We must concentrate our resources and talents, unleash the full potential of our scientists, and make breakthroughs in key fields," he said.

Zhang said the technology for quantum communication is relatively mature, especially for quantum key distribution. "China is currently leading in the field of quantum communication, but other countries are catching up," he added.

This mode of communication is unhackable due to the encryption keys being encoded in particles that are in a delicate, entangled quantum state. Any attempt to intercept them would disrupt that state and signal the presence of an eavesdropper.

Some banks in China are now sending ultra-secured transactions along the Jing-Hu Trunk Line, a 2,000-kilometer quantum communication line connecting Beijing, Jinan, Hefei and Shanghai, which was launched in 2017.

"This quantum communication service is still in early trials but the response so far is very satisfactory," Zhang said. "But whether this technology could be expanded to more areas will need more appraisal and certification from government and regulatory agencies."

In terms of quantum computing, tech giants such as Google, IBM, Amazon and Microsoft, along with smaller companies including Rigetti and D-Wave, are racing to create the world's first commercial quantum computer.

Unlike classical computers, which handle data in 0 or 1 binary bits, quantum computers process data using quantum bits, or qubits, that can exist in either 0, 1, or both. As a result, the computing power of quantum computers can increase exponentially as the number of qubits increases.

The point at which a quantum computer can solve a problem that not even the most powerful supercomputer can solve in any reasonable amount of time is called quantum supremacy.

Last year, Google claimed it had reached this milestone by using a 53-qubit processor named Sycamore to solve an arbitrary mathematical computation in 200 seconds. The same problem would take the world's most powerful supercomputer, the Summit, over 10,000 years, according to a study published in the journal Nature.

However, IBM, the creator of Summit, later challenged Google's findings by adjusting the way its supercomputer approached the task and said it could come up with a solution in 2.5 days.

Yuan Zhensheng, a professor of quantum information at USTC, said quantum computing excels in solving complex problems that require processing a large amount of data or calculations, such as creating new drug molecules and weather forecasting, but it may take years before the technology can mature.

"The theoretical framework for quantum computing is established, and we already know what issues need to be overcome to make it practical, the hard part is solving these difficult engineering challenges," he said.

For example, most quantum computers need to operate at a temperature close to absolute zero (-273.15 C) and in an extremely clean setting with low electromagnetic interference in order to avoid decoherence, a process in which the environment disturb the qubits and causes errors.

Breakthroughs envisioned

"We may see some major breakthroughs in quantum computing within the next five to 10 years," he said. "Ordinary people may not need such a powerful and complex machine in their home, so it is unlikely that quantum computers will replace today's computers."

"As we make our way to building a practical quantum computer, we may stumble upon new materials and discoveries that can also benefit society," he said. "Such is the beauty of pushing the boundaries of science into unknown territory."