  We investigate how robust is the modified XX spin-1/2 chain of [R. Vieira and
G. Rigolin, Phys. Lett. A 382, 2586 (2018)] in transmitting entanglement when
several types of disorder and noise are present. First, we consider how
deviations about the optimal settings that lead to almost perfect transmission
of a maximally entangled two-qubit state affect the entanglement reaching the
other side of the chain. Those deviations are modeled by static, dynamic, and
fluctuating disorder. We then study how spurious or undesired interactions and
external magnetic fields diminish the entanglement transmitted through the
chain. For chains of the order of hundreds of qubits, we show for all types of
disorder and noise here studied that the system is not appreciably affected
when we have weak disorder (deviations of less than 1% about the optimal
settings) and that for moderate disorder it still beats the standard and
ordered XX model when deployed to accomplish the same task.
