Characterizing mixed-state entanglement through single-photon interference

Entanglement verification and measurement is essential for experimental tests of quantum mechanics also communication information science. Standard methods verifying entanglement in a bipartite mixed state require detection both particles involve coincidence measurement. We present method that enables us to verify measure two-photon without detecting one the photons, i.e., performing any or postselection. consider two identical sources, each which can generate same but they never emit simultaneously. show produce set single-photon interference patterns, contain about state. prove it possible retrieve from visibility patterns. Our reveals distinct avenue measuring states.