Measurement-device-independent quantum key distribution protocols against collective noise

Abstract

In order to eliminate the influence of the channel noise, two new measurement-device-independent quantum key distribution (MDI-QKD) protocols are proposed with logical quantum states. They can resist collective-dephasing noise and collective-rotation noise, respectively. This paper produces logical quantum states by adding the auxiliary light sources, the CNOT operations and the Hadamard transforms in the system model. The main light sources and auxiliary light sources are flexible and easily implemented, since they can be weak coherent state (WCS) sources, heralded single-photon sources (HSPSs) or heralded pair coherent state (HPCS) sources. To generate one key bit, the new MDI-QKD protocols only need one logical qubit with two particles so that they have high qubit efficiency. Moreover, the new protocols also use partial Bell-state measurement (BSM) which is very easily implemented with existing technologies.