Feasibility of space-based measurement-device-independent quantum key distribution

TL;DR

This paper assesses the feasibility of space-based measurement-device-independent quantum key distribution using the Micius satellite, analyzing factors like high-loss uplinks, limited visibility, and two-photon interference requirements to guide future satellite quantum communication.

Contribution

It provides a comprehensive framework integrating orbital and atmospheric models to evaluate key parameters and interference considerations for implementing space-based MDI-QKD.

Findings

Feasibility of space-based MDI-QKD with current satellite technology.

Tradeoffs between orbit parameters and key rate improvements.

Strategies for two-photon interference and synchronization in dynamic channels.

Abstract

The measurement-device-independent (MDI) QKD is considered to be an alternative to overcome the currently trusted satellite paradigm. However, the feasibility of the space-based MDI-QKD remains unclear in terms of the factors: the high-loss uplink between a ground station and a satellite, the limited duration when two ground stations are simultaneously visible, as well as the rigorous requirements for the two-photon interference when performing the Bell-state Measurement (BSM). In this paper, we present a feasibility assessment of space-based MDI-QKD based on the Micius satellite. Integrated with the orbital dynamics model and atmosphere channel model, a framework is presented to explore the whole parameters space including orbit height, elevation angle, apertures of transceiver and atmospheric turbulence intensity to give the considerations for improving key rates and subsequently provide a relevant parameter tradeoff for the implementation of space-based MDI-QKD. We further investigate the heart of MDI-QKD, the two-photon interference considerations such as the frequency calibration and time synchronization technology against Doppler shift, and the way of performing the intensity optimization method in the dynamic and asymmetric channels. Our work can be used as a pathfinder to support decisions involving as the selection of the future quantum communication satellite missions.