The interpretations of the delayed-choice experiments suggest that photons "retroactively decide" to travel as particles or as wave from the time of its emission. To test the interpretations thoroughly, we propose and perform extended-delayed-choice experiments. The experiments are designed for easier to set up, carry out and reach meaningful results without ambiguous. The experimental results show the following: (A) the causality holds; (B) Bohr's complementarity principle is violated; (C) photons behave as particle before striking at output beam splitter/double-slit/crossdouble-slit; (D) the present does not determine the past retroactively, but determines the future.
The interpretations of the delayed-choice experiments suggest that photons "retroactively decide" to travel as particles or as wave from the time of its emission. To test the interpretations thoroughly, we propose and perform extended-delayed-choice experiments. The experiments are designed for easier to set up, carry out and reach meaningful results without ambiguous. The experimental results show the following: (A) the causality holds; (B) Bohr's complementarity principle is violated; (C) photons behave as particle before striking at output beam splitter/double-slit/crossdouble-slit; (D) the present does not determine the past retroactively, but determines the future.
The interpretations of the delayed-choice experiments suggest that photons i°retroactively decidei± to travel as particles or as waves from the time of its emission. To test the interpretations thoroughly, we propose and perform novel extended-delayed-choice experiments. The experiments are designed for easier to set up, carry out and reach meaningful results without ambiguity. The experimental results show the following: (A) The present does not decide the past retroactively, i.e., the causality holds; (B) Bohri¯s complementarity principle is challenged; (C) photons behave as particle before striking on a double-slit/cross-double-slit; (D) Particle nature is intrinsic.
We have performed cross-double-slit experiment and delayed-choice-cross-double-slit experiment, denoted as extended double-slit experiments. The cross-double-slit experiments show that the cross-double-slit apparatus creates not only two interference patterns, but also four cross-interference-patterns, which are created by two double-slit. The delayed-choice-cross-double-slit experiments disclose new phenomena: (1) photons behave as both wave and particle in the same experiment simultaneously, which violate Bohr’s complementarity; (2) the cross-interference-pattern is created by one double-slit and one single-slit; (3) photons passing through the same slit behave as both wave and particle, referred it as the Wave-Particle-Paradox, which demands extensive study. We suggest to re-study wave-particle duality.
Young's double slit experiments representing the mystery of quantum mechanics have been descripted by wave theories. To study the mystery, the double slit experiments were extended to the cross-double slit experiments. A description should explain all the double slit and cross-double slit experiments consistently. To test the wave description, the two postulates are proposed, which state that before passing through the double slit and before landing on the detector, photons behave as particles, but not as waves. To test the two postulates, the comprehensive double slit/cross-double slit experiments are proposed and performed. By placing shields and/or blockers near the detector/screen, the comprehensive double slit/cross-double slit experiments show that the fringes are created independently and partially, which discloses the particle nature of photons in the double slit/crossdouble slit experiments and violates the wave descriptions. The comprehensive double slit/cross-double slit experiments provide the comprehensive phenomena for developing theoretical model to study the mystery of double slit, complementarity principle, wave-particle duality, and wave theory of light.
Bohr's complementarity notion is at the heart of quantum physics. It suggests that quantum systems are observed as waves or particles depending on the type of measurement, i.e., the experimental arrangement, they are subjected to. For instance, sending single photons to an open or closed Mach-Zehnder interferometer (MZI) leads to the observation of particle or wave behaviours, respectively. In 1984, Wheeler proposed a "Gedanken" delayed-choice experiment in which the interferometer configuration is chosen at will by the experimentalist only after the photon has already passed the input beam-splitter (BS_in) of the device. This experiment was realized using a single photon source and showed that Bohr's complementarity notion was still obeyed.It was recently proposed to take Wheeler's experiment one step further by employing an output "quantum beam-splitter" (QBS), i.e.,preparing BS_out in a coherent superposition of being absent and present. This allows choosing the type of measurement, i.e., wave or particle, only after having determined the state of the QBS, which can be (in principle) infinitely delayed.We realized such an experiment by exploiting the resource of entanglement, in this case pairs of polarization entangled photons. The behaviour of one of the paired photons, called the test photon, is analysed using a MZI having a QBS at its output. This QBS is enabled by entanglement and made of a polarization dependent beam-splitter. The other photon, called the corroborative photon, allows determining the state of the QBS, and consequently, which test photon behaviour (wave, particle, or both) is observed.By manipulating the corroborative photon polarization state, we demonstrate a continuous morphing of the test photon from wave to particle behaviour. This refutes simple models of single photons behaving exclusively as waves or particles. The state of the QBS is determined via the measurement of the corroborative photon only after the test photon has already been detected. The space-like separation between the two measurements invalidates local-hidden variable models associated with pre-existing information about the measurement outcomes. In other words, when the test photon is detected, no information is available about the type of measurement it underwent. These results still perfectly obey Bohr's complementarity notion and its extension.
Abstract Young’s double slit experiments, which represent the mystery of quantum mechanics, have been interpreted by quantum probability waves and pilot waves. In this article, to study the mystery, we proposed and carried out comprehensive double slit experiments, which demonstrate two postulates related to double slit experiments: (1) before striking at the slide of a double slit, photons emitted by a laser source behave as particles; (2) before striking at the detector, photons behave as particles. Progress in studying the mystery of the double slit experiment is presented.