Microwave superconductivity and single-photon detectors

Almost any use of a superconductor implies a non-equilibrium state. Remarkably, while a sufficiently high-power electromagnetic field of GHz frequency can stimulate superconductivity, fast motion of magnetic flux quanta (Abrikosov vortices) can trigger an instability abruptly quenching the superconducting state.

We advance or delay the dynamic quenching of the vortex state in superconductors by tuning the power and frequency of the microwave ac stimulus added to a dc bias current. A cup of coffee in the image symbolizes the core of an Abrikosov vortex while the vapor cloud is an artistic representation of the wake of heated electrons which leave the vortex core upon its fast motion.

The fast relaxation of heated electrons at microwave frequencies is crucial for fast single-photon detectors made on the basis of superconductor thin films. The knowledge of the aborbed microwave power by vortices is also required for the manipulation of spin waves in superconductor-based nanoscale hybrid systems.

Recent publications

  • Upper frequency limits for vortex guiding and ratchet effects
    O. V. Dobrovolskiy, E. Begun, V. M. Bevz, R. Sachser, and M. Huth
    Phys. Rev. Appl. 13, 024012 (2020)
  • Different single photon response of wide and narrow superconducting MoSi strips
    Yu. P. Korneeva, N. N. Manova, I. N. Florya, M. Yu. Mikhailov, O. V. Dobrovolskiy, A. A. Korneev, and D. Yu. Vodolazov
    Phys. Rev. Appl. 13, 024011 (2020)
  • Moving flux quanta cool superconductors by a microwave breath
    O. V. Dobrovolskiy, C. Gonzalez-Ruano, A. Lara, R. Sachser, V. M. Bevz, V. A. Shklovskij, A. I. Bezuglyj, R. V. Vovk, M. Huth, F. G. Aliev
    Commun. Phys. 3, 64 (2020)
  • Microwave radiation detection with an ultra-thin and free standing superconducting niobium nano-helix
    S. Lösch, A. Alfonsov, O. V. Dobrovolskiy, R. Keil, V. Engemaier, S. Baunack, G. Li, O. G. Schmidt, and D. Bürger
    ACS Nano 13, 2948 (2019)
  • Reduction of microwave loss by mobile fluxons in grooved Nb films
    O. V. Dobrovolskiy, R. Sachser, V. M. Bevz, A. Lara, F. G. Aliev, V. A. Shklovskij, A. I. Bezuglyj, R. V. Vovk, and M. Huth,
    Phys. Stat. Sol. - Rap. Res. Lett. 13, 1800223 (2019)
  • Microwave emission from superconducting vortices in Mo/Si superlattices
    O. V. Dobrovolskiy, V. M. Bevz, M. Yu. Mikhailov, O. I. Yuzephovich, V. A. Shklovskij, R. V. Vovk, M. I. Tsindlekht, R. Sachser, and M. Huth,
    Nature Commun. 9, 4927 (2018)
  • Radiofrequency generation by coherently moving fluxons
    O. V. Dobrovolskiy, R. Sachser, M. Huth, V. A. Shklovskij, R. V. Vovk, V. M. Bevz, and M. Tsindlekht,
    Appl. Phys. Lett. 112, 152601 (2018)