There are several analogies between diffraction patterns and Josephson junctions, especially between a double slit experiment and two Josephson junctions in a superconducting ring (like this):
- Both are based on the interference of QM wavefunctions.
- The intensity pattern observed in diffraction experiments corresponds to the maximum supercurrent.
- The period of the pattern is determined by the ratio of the two slits compared to wavelength in optics whereas it depends on the ratio of the magnetic flux inside the ring to the flux quantum in superconductors.
- the fininte size of the slits and the finite size of the Josephson junction yield a sinc-envelope of the observed pattern.
In optics it's pretty clear to me what happens when the light passes the aperture. The aperture is a modification in r-space and we observe the distribution of k-vectors on the screen in the far field. E.g. the typical double slit aperture described by two delta functions convoluted with a rectangular function in r-space results in a cosinus diffraction pattern (Fourier transform of two delta functions) multiplied (convolution theorem) with a sinc (FT of a rect) in k-space / on the screen.
Question: What is the analogy of Fourier optics when talking about Josephson junctions? What are the domains (like k and r) that are involved?
Thank you very much!