Incoherent tunneling at weak bias: Strong quantum damping

Using a generalized version of Langer's “imaginary part of the free energy” method involving an “extended” bounce and doing a fully “dynamical” evaluation of the weak bias anomalous fluctuation mode, the thermal dependence of the decay rate Γ = A exp(-B) is studied for a metastable quartic potential model in the strong ohmic quantum damping regime in order to extend previous work to a considerably more realistic range of parameters. In particular, the earlier restrictions 12 B exp(-ħω₀/2k_BT)→0 and 2πk_BT/ħω₀→0 are removed. As a consequence there appear - inter alia - T² -corrections in B similar to those occuring for strongly biased metastable systems.