We present a quantitative study of the current-voltage characteristics (CVC)of diffusive superconductor/ insulator/ ferromagnet/ superconductor (SIFS)tunnel Josephson junctions. In order to obtain the CVC we calculate the densityof states (DOS) in the F/S bilayer for arbitrary length of the ferromagneticlayer, using quasiclassical theory. For a ferromagnetic layer thickness largerthan the characteristic penetration depth of the superconducting condensateinto the F layer, we find an analytical expression which agrees with the DOSobtained from a self-consistent numerical method. We discuss general propertiesof the DOS and its dependence on the parameters of the ferromagnetic layer. Inparticular we focus our analysis on the DOS oscillations at the Fermi energy.Using the numerically obtained DOS we calculate the corresponding CVC anddiscuss their properties. Finally, we use CVC to calculate the macroscopicquantum tunneling (MQT) escape rate for the current biased SIFS junctions bytaking into account the dissipative correction due to the quasiparticletunneling. We show that the influence of the quasiparticle dissipation on themacroscopic quantum dynamics of SIFS junctions is small, which is an advantageof SIFS junctions for superconducting qubits applications.
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