  A new method of preparation of radio-frequency superconducting quantum
interference devices on MgB2 thin films is presented. The variable-thickness
bridge was prepared by a combination of optical lithography and of the
scratching by an atomic force microscope. The critical current of the
nanobridge was 0.35 uA at 4.2 K. Non-contact measurements of the current-phase
characteristics and of the critical current vs. temperature have been
investigated on our structures.
