Multisite spin hopping analysis of multilevel dissipative quantum tunneling and coherence at finite temperatures

The novel (pseudo-)spin hopping analysis of real-time quantum mechanical motion at nonzero temperature in a dissipative double-well potential - as presented in parts I - III - is generalized to include a bias energy between the two wells. The general theory of part I - ab initio based on the Zwanzig-Caldeira-Leggett model-Hamiltonian for the unbiased potential - has been evaluated in the weak spin-bath coupling limit in part II while a strong coupling “noninteracting-blips” type treatment has been given in part III. In the present article (IV) the biased system is analyzed in both weak and strong coupling regimes.