A researcher from the University of Toronto is part of a global group of experts who, in principle, have demonstrated a device that can serve as the basis of the quantum Internet.
Hoi kwong loA professor at the Department of Electrical Engineering and Computer Engineering at the Faculty of Applied Science and Technology and his staff developed a prototype for the key element of fully photon quantum repeaters, a critical step in quantum communication at large distances.
“A fully optical network is a promising form of infrastructure for fast and energy-efficient communications, which is necessary for the future quantum Internet,” says Lo, who is appointed to the Faculty of Physics at the Faculty of Arts and Sciences.
The quantum Internet is considered the holy grail of quantum information processing, which allows the use of many new applications, including information-theoretic secure communication. In contrast, modern Internet has not been specifically designed for security, and this shows that hacking, hacking, and computer espionage are common problems. Unholy hackers are constantly breaking holes in the complex layers of protection erected by individuals, corporations, and governments.
In light of this, the researchers proposed other data transfer methods that could use the key functions of quantum physics to provide virtually unbreakable encryption. One of the most promising technologies includes a method known as quantum key distribution or QKD. QKD uses the fact that the simple act of measuring or measuring the state of a quantum system violates this system. Because of this, eavesdropping by a third party will leave behind a detectable trace, and the connection may be interrupted before the loss of confidential information.
Until now, this type of quantum security has been demonstrated only in small systems. Luo and his team are part of a group of global researchers who lay the foundation for the future quantum Internet, solving some of the problems of transmitting quantum information over long distances using fiber optic communications.
Since light signals lose their power because they travel long distances along fiber optic cables, devices, called repeaters, are installed at regular intervals along the line. Repeaters amplify and amplify signals to help transmit information.
But existing repeaters for quantum information are quite problematic. They require quantum state storage at repeater sites, which makes repeaters prone to errors, difficult to assemble, and very expensive because they often work at cryogenic temperatures.
Lo and his team suggested a different approach. They are working to create next-generation repeaters, called fully photon quantum repeaters, that will eliminate or reduce many of the shortcomings of standard quantum repeaters. With staff from Osaka University, Toyama University and NTT Corporation in Japan, Luo and his team demonstrated their work in a recently published article Nature connection,
“We have developed fully photon repeaters that allow Bell’s adaptive measurement with time reversal,” says Lo.
“Since these repeaters are completely optical, they offer advantages that traditional – repeaters – based on quantum memory – do not have. For example, this method can work at room temperature. "
Quantum Internet can offer applications that cannot be implemented on the regular Internet, such as impenetrable security and quantum teleportation, which uses the phenomenon of quantum entanglement to transfer information between atoms separated by large distances.
“Our work helps pave the way to this future,” says Lo.
The study was funded, among other things, by the Natural Science and Engineering Research Council of Canada.