Diode effect in superconducting Nb$_3$Sn micro-bridges at high frequencies

The superconducting diode effect has been recently reported in a variety of systems. Various symmetry breaking mechanisms have been examined. However, frequency ranges of these potentially important devices are still obscure. We investigated superconducting micro-bridges of Nb$_{3}$Sn with a relatively large diode efficiency of $\sim$ 5% using an out-of-plane magnetic field as small as 2.5 mT; optimum magnetic fields (up to 10 mT) generate higher efficiency (up to 10%) while higher fields, $\sim$ 15-20 mT, quench the effect. The diode changes its polarity with the magnetic field. Interestingly, the bridge resistance at diode operation reaches a value with a factor of 2 times smaller than in its normal state, which is compatible with the vortex-caused mechanism of resistivity. Further confirmation of this mechanism was revealed by scanning electron microscopy: dissimilar edges of the superconductor strip can be responsible for the inversion symmetry breaking. Superconductive diode rectification was observed at frequencies up to 100 kHz, the highest reported as of today. Estimates are in favor of much higher, GHz, range of frequencies