2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/169559We describe a general method of realizing entanglement witnesses in terms of the interference pattern of a single quantum probe. After outlining the principle, we discuss specific realizations both with electrons in mesoscopic Aharonov-Bohm rings and with photons in standard Young's double-slit or coherent-backscattering interferometers.5 pages, 3 figures, epl2, uses pstricks.styQuantum PhysicsMesoscale and Nanoscale Physicstext