Using an experimental setup that simulates a turbulent atmosphere, we study the secret key rate for quantum key distribution protocols in orbital angular momentum based free space quantum communication. The quantum key distribution protocols under consideration include the Ekert 91 protocol for different choices of mutually unbiased bases and the six-state protocol. We find that the secret key rate of these protocols decay to zero roughly at the same scale where the entanglement of formation decays to zero.
@article{arxiv.1412.0788,
title = {Experimental orbital angular momentum based quantum key distribution through turbulence},
author = {Sandeep Goyal and Alpha Hamadou Ibrahim and Filippus S. Roux and Thomas Konrad and Andrew Forbes},
journal= {arXiv preprint arXiv:1412.0788},
year = {2014}
}