Quantum fluctuations in thin superconducting wires of finite length

Abstract

In one dimensional wires, fluctuations destroy superconducting long-range order and stiffness at finite temperatures; in an infinite wire, quasi-long range order and stiffness survive at zero temperature if the wire's dimensionless admittance $\mu$ is large, $\mu > 2$. We analyze the disappearance of this superconductor-insulator quantum phase transition in a finite wire and its resurrection due to the wire's coupling to its environment characterized through the dimensionless conductance $K$. Integrating over phase slips, we determine the flow of couplings and establish the $\mu$--$K$ phase diagram.