Experimental comparison of various quantum key distribution protocols under reference frame rotation and fuctuation

TL;DR

This study experimentally compares various quantum key distribution protocols, demonstrating that reference-frame-independent QKD (RFI-QKD) is more robust against reference frame rotation and fluctuation in free-space conditions.

Contribution

The paper provides the first experimental verification of RFI-QKD's robustness compared to other protocols under reference frame disturbances.

Findings

RFI-QKD outperforms BB84 and six-state protocols under rotation and fluctuation.

Experimental setup successfully implements multiple QKD protocols.

RFI-QKD maintains higher key rates despite reference frame disturbances.

Abstract

In free-space quantum key distribution (QKD) between moving parties, e.g., free-space QKD via satellite, the reference frame rotation and fluctuation degrades the performance of QKD. Reference-frame-independent QKD (RFI-QKD) provides a simple but efficient way to overcome this problem. While there has been a number of theoretical and experimental studies on RFI-QKD, the experimental verification of the robustness of RFI-QKD over other QKD protocols under the reference frame rotation and fluctuation is still missing. Here, we have constructed a free-space QKD system which can implement BB84, six-state, and RFI-QKD protocols, and compared their performances under the reference frame rotation and fluctuation. With the theoretical analysis and experimental data, we have successfully verified the robustness of RFI-QKD protocol over other QKD protocols in the presence of reference frame rotation and fluctuation.