  We study the signatures of disorder in the production of orbital electron
entanglement in quantum wires. Disordered entanglers suffer the effects of
localization of the electron wave function and random fluctuations in the
entanglement production. This manifests in the statistics of the concurrence, a
measure of the produced two-qubit entanglement. We calculate the concurrence
distribution as a function of the disorder strength within a random-matrix
approach. We also identify significant constraints on the entanglement
production as a consequence of the breaking/preservation of time-reversal
invariance. Additionally, our theoretical results are independently supported
by simulations of disordered quantum wires based on a tight-binding model.
