Relaxation electrodynamics of superinsulators

Superinsulators offer a unique laboratory realizing strong interaction phenomena like confinement and asymptotic freedom in quantum materials. Recent experiments evidenced that superinsulators are the mirror-twins of superconductors with reversed electric and magnetic field effects. Cooper pairs and Cooper holes in the superinsulator are confined into neutral electric pions by electric strings, with the Cooper pairs playing the role of quarks. Here we report the non-equilibrium relaxation of the electric pions in superinsulating films. We find that the time delay t (sh) of the current passage in the superinsulator is related to the applied voltage V via the power law, t(sh) alpha (V - V-p)(-mu), where V-p is the effective threshold voltage. Two distinct critical exponents, mu = 1/ 2 and mu = 3/ 4, correspond to jumps from the electric Meissner state to the mixed state and to the superinsulating resistive state with broken charge confinement, respectively. The mu = 1/ 2 value establishes a direct experimental evidence for the electric strings' linear potential confining the charges of opposite signs in the electric Meissner state and effectively rules out disorder-induced localization as a mechanism for superinsulation. We further report the memory effects and their corresponding dynamic critical exponents arising upon the sudden reversal of the applied voltage. Our observations open routes for exploring fundamental strong interaction charge confinement via desktop experiments.

Automated summary

Superinsulators, the mirror-twins of superconductors, have been studied to explore strong interaction charge confinement. This research reports the non-equilibrium relaxation of electric pions in superinsulator films and reveals power law relationships and critical exponents associated with applied voltage and electric field effects. The findings provide experimental evidence for electric strings' linear potential confining opposite charges and open new routes for studying fundamental strong interaction phenomena.