  We have investigated the proximity effect in superconductor/ferromagnet
junctions in a systematic manner to discuss the relationship between the
zero-energy peak (ZEP) of the local density of states (LDOS) and spin-triplet
odd-frequency pairing. By exactly solving the nonlinear Usadel equations, we
have found that the ZEP is realized in a wide range of geometrical and material
parameters in the case of the noncollinear magnetization. This strongly
suggests the robustness of the ZEP induced by spin-triplet odd-frequency
pairing in such systems. We also found that the crossover from singlet pairing
to triplet pairing can be detected by measuring the F layer thickness
dependence of the ZEP height. Furthermore, we show how to observe signatures of
spin-triplet odd-frequency pairing and the pairing crossover by LDOS
measurement. Our results provide a direct way to experimentally detect
signatures of the odd-frequency pairing state.
