Researchers from RDECOM Research Laboratory developed a method to filter noise of quantum information
A team of researchers from RDECOM Research Laboratory, the U.S Army’s Corporate Research Laboratory (ARL) discovered a new approach to protect quantum information during transmission. The research is expected to facilitate development of highly secure and reliable communication for defense and military purpose. Quantum Information Science (QIS) is a field of science that studies information encoded in quantum systems and encompasses quantum computing, quantum communication, and quantum sensing among other subfields. ARL is focused on investing in QIS research for development of superior technologies in computation, encryption, secure communication, and precise measurements. Development of robust methods is required to process and transmit filtering noise to utilize quantum information.
Filtering is a straightforward process in classical communications as it is done in the very place the information is received. The team was focused on devising new approaches for filtering noise from small bits of quantum information known as quantum bits or qubits that are sent across fiber-optic telecom links. The RDECOM Research Laboratory research set an experiment on the Quantum Networking Testbed as part of their work to offer more secure and reliable communication. The team found that filtering does not necessarily need to be performed by the receiver (of information). According to Brian T. Kirby of ARL, the nature of the quantum states in which the information is encoded allows easy filtering at a different location in the network. Therefore, to fix a qubit sent over a certain route, a filter can be applied to other qubits that traverse a different route.
The team was focused on understanding physical properties of real telecom fibers including inherent residual birefringence and polarization dependent loss that affect the quality of quantum communications. A new mathematical approach was devised that enabled the development of a simple and elegant geometrical model of the polarization dependent loss effects on polarization entanglement. The model predicted quality of transmitted quantum states and the required rate of quantum information transmission. Moreover, the team devised a new technique to reduce the deleterious effects of the noise. Quantum Networking Testbed, which simulates the practical telecom fiber infrastructure, was used to experimentally validate the developed models.