Finite Size Scaling Behavior of Dissipative Tunnel Junctions

We present the results of a series of Quantum Monte Carlo calculations of the temperature dependent conductance of dissipative non-superconducting tunnel junctions. Finite size scaling methods are used to demonstrate the absence of coherent transport in Ohmic tunnel junctions. However, a quantum phase transition between coherent and incoherent behavior is found in sub-Ohmic tunnel junctions. The critical conductance is found to be temperature independent and the critical exponents, $\nu$ and $\eta$, are found to be in agreement with renormalization group results by Kosterlitz.