Interference, diffraction, and diode effects in superconducting array in S-TI-S lateral Josephson junctions

It is a well-known phenomenon in optics that the spectroscopic resolution of a diffraction grating is much better compared to an interference device having just two slits, as in Young's double-slit experiment. On the other hand, it is well known that a classical superconducting quantum interference device (SQUID) is analogous to the optical double-slit experiment. Here we present experimental results and a model describing a superconducting analogue to the diffraction grating, namely an S-TI-S lateral Josephson junction array positioned on a topological insulator (TI) film Bi0.8Sb1.2Te3. Such devices exhibit a critical current peak that is much sharper than the analogous peak of an ordinary SQUID in the limit of an extremely weak field. They can be used as a sensitive absolute magnetic field sensors. They can also act as superconducting diodes due to their inherent asymmetry.