Superconductor-insulator transition in disordered Josephson junction chains
Starting from a lattice model for Josephson junction chains that includes capacitive couplings to the ground as well junction capacitances, we derive the effective low-energy field theory. The transition to the insulating state is driven by the proliferation of quantum phase slips. The most important source of disorder originates from trapped charges in the substrate that suppress the coherence of phase slips, thus favoring superconducting correlations. Using the renormalization-group approach, we determine the phase diagram and evaluate the temperature dependence of the dc conductivity and system-size dependence of the resistance around the superconductor-insulator transition. Due to the interplay of superconductivity and disorder, these dependences have in general a strongly non-monotonic character.