Quantum Tunneling of Nonlinear Klein-Gordon System with Dissipation in High External Field

Abstract

We investigate the tunneling rate from metastable state induced by the external applied field in the nonlinear Klein-Gordon system with dissipation. By the scaling argument, it is shown that the effective dissipation becomes strong as the external field approaches the classical depinning field and qualitatively changes the external field dependence of tunneling rate. For arbitrary strength of the effective dissipation, the tunneling rate is obtained by the variational method.