We demonstrate the quantum Talbot effect using a beam of single photons produced by parametric down conversion. In contrast to the previous works, we use a programmable spatial light modulator to behave as a diffraction grating. Thus, the investigation of the Talbot diffraction patterns under the variation of grating structure can be easily performed. The influence of spectral bandwidth of the down-converted photons on the diffraction pattern is also investigated. A theoretical model based on the wave nature of photons is presented to explain the Talbot diffraction patterns under varying conditions. The measured diffraction patterns are in good agreement with the theoretical prediction. We are convinced that our study improves the understanding of the quantum Talbot effect.
Electron diffraction is not solely a powerful method to study fundamental physics but has also been applied to quantum sensors. A low-coherence electron source results in a drop of fringe contrast. One approach to enhance a visibility of the diffraction pattern is to improve a longitudinal coherence of an electron beam. When electrons pass through a magnetic field, they experience a force which bends them to circular paths. Electrons with different energies will travel along the different paths. By placing a slit behind the magnetic field, the width of the electron energy distribution will become narrower and hence an improvement of the beam coherence. However, this method reduces the intensity of the electron beam. The simulation was performed to optimize the slit width for electron diffraction experiments with respect to the energy spread of the beam and electron flux.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.