Satellite communication over quantum channel

László Bacsárdi, László Gyöngyösi, Sándor Imre

Cristian Bonato, Andrea Tomaello, Vania Da Deppo +2 more

Sonai Biswas, Riccardo Bassoli, Janis Nötzel +3 more

Min Nie, Shang Peng-Gang, Yang Guang +2 more

Mesoscale sandstorm is a common form of dust weather in Nevada in the US, the northern part in China, and the Middle East countries in the Asia. To investigate the influence of mesoscale sandstorm on the quantum satellite communication channels, the physical characteristics of the dust storms are analyzed first. According to the diffusion model of mesoscale storms, the relationship between the proposed scale dust features and the degree of quantum entanglement is established then. The effect of dust on properties of the quantum satellite channel is simulated finally. The results show that if the diffusion time for the dust is 12 hours, the dust particle radii are 1 and 25 μm, the entanglement degrees of quantum satellite channels are 0.6 and 0.4, the utilization rates of quantum satellite channels are 0.9 and 0.8, the capacities of quantum satellite channels are 0.95 and 0.8. The characteristic parameters of the quantum channels are closely related to sandstorms. Therefore, in order to improve the reliability of quantum satellite communications, the parameters of quantum satellite channels should be adjusted adaptively.

Patrick Gélard, Laurent de Forges de Parny

László Bacsárdi

Abstract Quantum computing offers revolutionary solutions in the field of computer sciences, applying the opportunities of quantum physics which are incomparably richer than classical physics. Although quantum computers are going to be the tools of the far future, there are already a few algorithms to solve problems which are very difficult to handle with traditional computers. Perhaps the easiest example of a structure of a quantum system is a quantum channel. Typically, one is interested in some basis in the Hilbert space representing the input of a channel, which is entangled with a second Hilbert space representing the environment, and then another (possibly the same) basis for the first space at a later time. Free-space quantum key distribution (QKD)—over an optical path of about 30 cm—was first introduced in 1991, and recent advances have led to demonstrations. Indeed there are certain key distribution problems in this category for which free-space QKD has practical advantages (for example it is not practical to send a courier to a satellite). Quantum computing algorithms can be used to affirm our communication in several ways (open-air communication, satellite communications, satellite broadcast, satellite-satellite communication). We set up a free-space quantum-channel-model at the university and made several simulations. The main aim is to trace some adoptable algorithms in the communication between Earth and the satellite and also between satellites. This paper is a theoretical study to compare the simulation results of the three models.