  We investigate the decay properties of the quantumness including quantum
entanglement, quantum discord and quantum coherence for two photonic qubits,
which are partially entangled in their orbital angular momenta, through
Kolmogorov turbulent atmosphere. It is found that the decay of quantum
coherence and quantum discord may be qualitatively different from that of
quantum entanglement when the initial state of two photons is not maximally
entangled. We also derive two universal decay laws for quantum coherence and
quantum discord, respectively, and show that the decay of quantum coherence is
more robust than nonclassical correlations.
