Quantum entanglement in the double slit experiment with qubit which-path detectors

Abstract: After reviewing basic concepts and tools in order to quantify entanglement, a theoretical set up is proposed, which is based on the double slit experiment and the Mach-Zehnder interferometer. A particle, which is in a superposition of two paths, can interfere with a qubit on each path before it is scattered by a beam splitter and measured by two separate detectors. After a detailed investigation, it can be shown that it is possible to induce entanglement to the qubits via post-selection. This means that the measurement does not induce entanglement, but can be used to select the entangled qubits after a number of iterations. A remarkable result is, that this works independently from the probability of interaction between the particle and the qubits, which could turn out be very beneficial in a possible realization of the set up.