Macroscopic quantum tunneling in one-dimensional superconducting wires

Macroscopic quantum tunneling in a one-dimensional superconductor is discussed using the microscopic model near the critical temperature. By means of a functional integral approach, we derive the total decay rate as the sum of the thermal activation and quantum mechanical tunneling rate. The theory is tested experimentally by measuring the resistance of a superconducting wire. It is found that the theory for the tunneling rate is consistent with experimental results and that it is adequate for temperatures at which the thermal activation theory fails.