Research team makes quantum computing breakthrough
Wed 13 Apr 2016
A group of scientists from ITMO University in Saint Petersburg and Heriot-Watt University in Edinburgh have created a quantum computing device that can complete long-range transmissions of secure data.
The research team has a novel approach to quantum computing. Using side frequencies – oscillations that appear alongside the main carrier frequency – the experimental quantum computing device is capable of transmitting single-photon quantum signals via optical fiber over 250 kilometers. “In terms of bit rate and operating distance our system is comparable to absolute champions in the field of quantum communications,” said Artur Gleim, head of the Quantum Information Center at ITMO University.
Encoding quantum bits in this manner uses a laser to split central carrier waves into several independent waves. This creates the side frequencies that are used to transmit data. The information is transmitted, and the same splitting occurs on the receiving end. The relative phase shift of waves between the sender and receiver is used to make a pattern of overlapping wave phases that can be converted into binary digits. The binary is then used to compile the quantum key.
Thus far the key has been successfully transmitted using side frequency modulation. “Now the researchers are on the mission to create a full-fledged quantum cryptographic system, which will generate and distribute quantum keys and transmit useful data simultaneously,” said the ITMO press service. Using side frequencies as a transmission device also allows a unique device architecture that may be more efficient for practical use.
Gleim stated “This unique approach gives us a number of advantages, such as considerable simplification of the device architecture and large pass-through capacity of the quantum channel.” This method of data transfer could also be used with existing fiber optic infrastructure. Robert Collins, research associate at Herriot-Watt University noted, “Down the track, this new approach can enable smooth coexistence of numerous data streams with different wavelengths in one single optical cable … these quantum streams can be fed into the already existing fiber optic lines along with conventional communications.”
Information security is a growing concern, as the complexity data encryption algorithms is changing at the same pace as the sophistication of hacking techniques. Quantum computing systems, on the other hand, protect information using the fundamental laws of quantum physics. Because quantum-channel information changes in the event it is intercepted between the sender and receiver, the primary information would be protected and users would know immediately if an unauthorized intercept had occurred.