Dynamical mass of a quantum vortex in a Josephson junction array
Ulrich Eckern, Giuseppe Gaetano Luciano, A. Tagliacozzo · Physical review. B, Condensed matter · 1997
The real-time response to a small external perturbation of a vortex in a quantum Josephson junction array, with long-range Coulomb interaction between Cooper pairs, is analyzed. While the static damping is zero for vortex velocities below some threshold value ${v}_{\mathrm{th}}$ (which implies the possibility of ballistic motion), a dynamical friction due to the coupling to the plasma oscillations is always present for frequencies higher than a given threshold ${\ensuremath{\omega}}_{\mathrm{th}}.$ The latter approaches zero when the velocity increases to ${v}_{\mathrm{th}}.$ However, radiative dissipation of the vortex affects the threshold for ballistic motion. We discuss the conditions under which a mass can be defined for the vortex as a quantum particle.