Proposal for a Simple Variant of the Quantum Eraser Experiment to Discriminate Between Logical and Physical Causes of Interference Loss

This short proposal presents a novel and conceptually simple variant of the quantum eraser experiment aimed at addressing a fundamental question: is the disappearance of interference in quantum systems due to physical interaction, or merely to the logical knowability of which-path information? In the standard quantum eraser setup, path information is encoded using orthogonal polarizations and then erased by a single 45° polarizer after the beams are recombined. This proposal suggests a different configuration: placing two separate 45° polarizers before recombination—each attached to its respective H or V polarizer—to test whether interference can still reappear even though the path origin of each photon remains logically accessible. To the best of our knowledge, this dual-polarizer configuration has never been tested experimentally. Its outcome could provide valuable insight into whether interference is governed by physical indistinguishability or by the observer’s potential knowledge. The document includes a brief literature background, a detailed description of the proposed setup, and a discussion of the possible results and their interpretative consequences. The full text is provided in both English and Italian.