Two Achievements of the Department of Optics
Vladyslav Usenko (left) and Associate Professor Radim Filip.
Photo: Velena Mazochová
Olomouc opticians Vladyslav Usenko and Radim Filip marked the beginning of the new year with two notable results of their scientific work. The results of their research, which they performed with Danish colleagues, were published by the Nature Communications journal. In addition, they are working on an international project BRISQ2.
The common theme of the both successful achievements is the security of quantum communication using method of quantum cryptography. In contrast to traditional cryptographic methods it allows secure transmission of data based on the laws of quantum physics. Its main benefit is the ability to detect interception of the transferred data. Instead of the message the auxiliary cryptographic key is transmitted. If interception is detected, then the key will not be used and no information will leak. If the key is transmitted securely, it will be used to encrypt the message.
The safest encryption key
It is the application of new methods of quantum optics to quantum key distribution that is the major area of research of Vladyslav Usenko, who joined the Department of Olomouc after his post-doctoral studies in Milan. Together with Associate Professor Filip he theoretically “predicted” the usefulness of the squeezed states of light for secure key distribution.
"Our calculations show that even the weakly squeezed quantum fluctuations of light are able to increase the distance over which the key can be safely transferred. It was previously considered impossible, so our discovery was so inspiring for Danish experimentalists, that they decided to measure it at once”, says Usenko.
Publication of the experimental proof in the prestigious scientific journal is also the main outcome of his post-doctoral project. "His example confirms that the effort to attract young, high-quality foreign scientists is a positive way to the further development of the scientific potential of the Department," says Filip.
Head of Department Professor Zdeněk Hradil says that Usenko’s example can be followed by means of the newly launched university-wide project POSTUP. "The newly created post-doctoral positions represent a chance for more young foreign scientists. It will depend only on their qualities, "says Hradil.
Contentment at the Department is mutual. "Already during my doctoral studies from the many publications from Olomouc I knew that there is a strong scientific group focused on quantum optics. Department of Optics is an excellent place for my scientific development, "says Usenko, who took the opportunity to work in Olomouc after the end of his study period.
International project as recognition of scientific excellence
The increase of security of quantum cryptography is also aimed at in the three-year international project called BRISQ2, which was won by Olomouc scientists along with the four other teams from Italy, Germany and Poland. "It deals with aspects of macroscopic quantum squeezed states of light and their applications in quantum communication. We believe that we will be able to demonstrate their usefulness", describes Filip the objective of the project.
Winning the project means keeping the high professional level for the Department of Optics. “The contest is really challenging and many excellent scientific groups from the Western Europe often fail in it”, comments Filip the prestigiousness of the project. He adds that the main investigators from the Max-Planck Institute in Erlangen, Germany, are the long-term partners of the Derpartment.
The Head of the International Centre for information and uncertainty, Associate Professor Jaromír Fiurášek confirms that the participation of the Department of Optics in European projects became traditional during the last ten years. "This project further enhances the position of the Department on the international scale," adds Fiurášek.
