Quantum fluctuations and dissipative phase transition in one-dimensional Josephson junction arrays

We studied superconductor–insulator transition in one-dimensional arrays of small Josephson junctions in which each junction was shunted by ohmic resistor. The I–V characteristics changed from Coulomb-blockade type behavior to Josephson-like one with decreasing shunt resistance RS, even when the Josephson coupling energy EJ was much smaller than the charging energy View the MathML source, View the MathML source. The critical value of RS was close to View the MathML source for EJ/EC smaller than unity. This agrees with theoretical predictions for dissipation-driven phase transitions in this system.