Experimental Quantum Communication without a Shared Reference Frame

摘要

We present an experimental realization of a robust quantum communicationscheme [Phys. Rev. Lett. 93, 220501 (2004)] using pairs of photons entangled inpolarization and time. Our method overcomes errors due to collective rotationof the polarization modes (e.g., birefringence in optical fiber ormisalignment), is insensitive to the phase's fluctuation of the interferometer,and does not require any shared reference frame including time reference,except the need to label different photons. The practical robustness of thescheme is further shown by implementing a variation of the Bennett-Brassard1984 quantum key distribution protocol over 1 km optical fiber.