Chinese scientists at the University of Science and Technology in Hefei, Anhui province, have engineered a breakthrough that could help bring high speed, quantum broadband communication a lot closer to reality than ever before.
Demonstrating that quantum information could be stored and distributed under a broadband communication protocol, the researchers said that the new technology “shows great promise for the establishment of quantum networks in high-speed communications.”
Quantum computing and encryption have become the latest fad among the research community due to their unhackable nature and this one of the many reasons why industries worldwide are closely monitoring quantum communications’ progress.
With companies and nations losing billions due to numerous hacking sprees, quantum broadband could be the best available remedy to stem this evil; anyone who tried to detect or measure the quantum bits, such as entangled photons that carry information in various quantum states, would unavoidably destroy the qubit, making the data impossible to read and alerting the recipient.
It is primarily these security reasons that the Chinese government has invested a huge amount of resources into quantum communication: The world’s longest quantum network and first quantum communication satellite are both currently being constructed in China.
Existing networks are however plagued by narrow bandwidth and slow speeds, mainly due to the difficulty of maintaining fragile quantum states over long distances. Quantum networks in use today are only able to distribute short key chains used to encrypt data transmitted on conventional networks, an improvement in security but not the dramatic step proposed by the new paper.
Professor Shi Baosen, one of the authors of the paper, said his team’s work was partly the result of intense international competition. Many countries are racing to develop the world’s first quantum communication “expressway,” said Shi.
Take for instance a UK team that added “fuel” to travelling qubits, swiftly increasing speed but simultaneously increasing instability, which finally resulted in more accidents.
That is why Shi’s team took a different approach; in addition to building “pump stations”, they also imposed restrictions to regulate the movement of qubits and slow them down when necessary. To achieve this they used laser to freeze fast moving photons and developed some new methods to control the network flow.
“Our cold approach is more sophisticated and required bulkier equipment setup, but it produced better results, which helped us win the race,” Shi said.
The new technology would not only be useful in high speed quantum communication, but shed new light on the construction of quantum computers as well. The broadband protocol, known as Raman quantum memory, allowed entangled photons to run around and around in a fiber loop with an optical switch that would release them whenever they were needed, thus providing a “memory chip” for quantum computers.
Lots of work remains to be done before the first quantum broadband network can be properly built. For instance, the laboratory setup is still too large, too sophisticated and too costly for mass application, cautions Shi.
Image courtesy of Reuters
