Simple quantum key distribution using a stable transmitter-receiver scheme

Quantum Key Distribution (QKD) is a technology that allows secure key exchange between two distant users. A widespread adoption of QKD requires the development simple, low-cost, and stable systems. However, implementation current complex self-alignment process during initial stage an additional hardware to compensate environmental disturbances. In this study, we have presented simple with help transmitter-receiver scheme, which simplifies robust enough withstand case stability test, system able remain for 48 hours exhibits average quantum bit error rate less than 1\% without any feedback control. The scheme also tested over fiber spool, obtaining finite 7.32k bits per second spool extending up 75 km. demonstrated long-term obtained prove our method promising alternative practical systems, in particular, Cubesat platform satellite applications.