  The entanglement dynamics of arrays of qubits is analysed in the presence of
some general sources of noise and disorder. In particular, we consider linear
chains of Josephson qubits in experimentally realistic conditions.
Electromagnetic and other (spin or boson) fluctuations due to the background
circuitry and surrounding substrate, finite temperature in the external
environment, and disorder in the initial preparation and the control parameters
are embedded into our model. We show that the amount of disorder that is
typically present in current experiments does not affect the entanglement
dynamics significantly, while the presence of noise can have a drastic
influence on the generation and propagation of entanglement. We examine under
which circumstances the system exhibits steady-state entanglement for both
short (N < 10) and long (N > 30) chains and show that, remarkably, there are
parameter regimes where the steady-state entanglement is strictly non-monotonic
as a function of the noise strength. We also present optimized schemes for
entanglement verification and quantification based on simple correlation
measurements that are experimentally more economic than state tomography.
