Air-to-air quantum key distribution with boundary layer effects

Abstract

Airborne platforms offer a potential solution to overcome the challenges of quantum key distribution (QKD) over long distances and in free space. However, the presence of boundary layer around high-speed flying vehicles can introduce unpredictable shifts and disturbances to transmitted photons, affecting their mode. In this article, we propose a performance evaluation scheme for air-to-air QKD with boundary layer effects. Our analysis compares the effects of the boundary layer at the receiver and at the transmitter on QKD performance, as well as an evaluation of two possible air-to-air QKD models. The results indicate that in the co-directional flight model, a particular azimuth can significantly increase the QBER when both ends are affected by the boundary layer, and photon deflection angles are larger when the transmitter is at a relatively low altitude. In the counter-directional flight model, the boundary layer around the aircraft may result in a maximum reduction in secure key rate by approximately 79.6% and introduce average channel loss of around 3.45 dB for transmitted photons. These findings highlight the importance of considering the boundary layer effects in air-to-air QKD and provide insights for the design and optimization of QKD systems in practical scenarios.

Keywords

• Boundary layer
• Air-to-air quantum key distribution
• Aero-optical effects