Quantum Diffraction

Wilhelm E. Frahn

Paul‐Antoine Moreau, Peter A. Morris, Ermes Toninelli +5 more

Quantum ghost diffraction harnesses quantum correlations to record diffraction or interference features using photons that have never interacted with the diffractive element. By designing an optical system in which the diffraction pattern can be produced by double slits of variable width either through a conventional diffraction scheme or a ghost diffraction scheme, we can explore the transition between the case where ghost diffraction behaves as conventional diffraction and the case where it does not. For conventional diffraction the angular extent increases as the scale of the diffracting object is reduced. By contrast, we show that no matter how small the scale of the diffracting object, the angular extent of the ghost diffraction is limited (by the transverse extent of the spatial correlations between beams). Our study is an experimental realisation of Popper's thought experiment on the validity of the Copenhagen interpretation of quantum mechanics. We discuss the implication of our results in this context and explain that it is compatible with, but not proof of, the Copenhagen interpretation.

Jian Ma

Motion of microscopic particles has been a very interesting topic.In order to explain the matter wave diffraction problem better,this paper using the new method of quantum theory to studies the Double-slit diffraction of C60 molecules using the new method of quantum theory.First,solve the Double slit diffraction of C60molecules wave functions by Schrodinger equation.Then calculate the diffraction wave function after the slit of C60 molecules with the Feynman path integral quantum theory.To obtain diffraction wave function of diffraction screen.Finally the analytic relation between the double-slit relative diffraction intensity and diffraction pattern position of C60molecules is obtained.The calculation results are in good agreement with the experimental data.This shows that the diffraction microscopic particles need to be studied with quantum theory method completely.This method has universality for the study of the motion of microscopic particles.It also can be used in the study of single slit diffraction, Multi-slit diffraction and grating diffraction for matter wave and other particles.

Pierre Meystre

Avijit Lahiri

Mathieu Beau, T. C. Dorlas

We study the quantum slit diffraction problem in three dimensions. In the treatment of diffraction of particles by a slit, it is usually assumed that the motion perpendicular to the slit is classical. Here we take into account the effect of the quantum nature of the motion perpendicular to the slit using the Green function approach [18]. We treat the diffraction of a Gaussian wave packet for general boundary conditions on the shutter. The difference between the standard and our three-dimensional slit diffraction models is analogous to the diffraction in time phenomenon introduced in [16]. We derive corrections to the standard formula for the diffraction pattern, and we point out situations in which this might be observable. In particular, we discuss the diffraction in space and time in the presence of gravity.