  Many-qubit entanglement is crucial for quantum information processing
although its exploitation is hindered by the detrimental effects of the
environment surrounding the many-qubit system. It is thus of importance to
study the dynamics of general multipartite nonclassical correlation, including
but not restricted to entanglement, under noise. We did this study for
four-qubit GHZ state under most common noises in an experiment and found that
nonclassical correlation is more robust than entanglement except when it is
imposed to dephasing channel. Quantum discord presents a sudden transition in
its dynamics for Pauli-X and Pauli-Y noises as well as Bell-diagonal states
interacting with dephasing reservoirs and it decays monotonically for Pauli-Z
and isotropic noises.
