Quantum key distribution without a shared reference frame
C. E. R. Souza, C. V. S. Borges, Antonio Zelaquett Khoury, J. A. O. Huguenin, Leandro Aolita, Stephen Patrick Walborn · Physical Review A · 2008
We report a simple quantum-key-distribution experiment in which Alice and Bob do not need to share a common polarization direction in order to send information. Logical qubits are encoded into nonseparable states of polarization and first-order transverse spatial modes of the same photon.