Relaxation electrodynamics of superinsulators

Abstract

Superinsulators, realizing a single-color version of quantum chromodynamics, offer a unique laboratory for exploring the fundamentals of confinement and asymptotic freedom via desktop experiments. Recent experiments [1] 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 pions by electric strings, with the Cooper pairs playing the role of quarks [1,2]. 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 ∝ (V − V p ) −µ , where V p is the effective threshold voltage. Two distinct critical exponents are found, µ = 1/2 and µ = 3/4, corresponding to jumps from the electric Meissner state to the mixed state and to the superinsulating resistive state with broken charge confinement, respectively. The exponent µ = 1/2 establishes a direct experimental evidence for the electric strings' linear potential confining the charges of opposite signs in the electric Meissner state. We further report memory effects and their corresponding dynamic critical exponents arising upon the sudden reversal of the applied voltage.