Nonstationary Josephson effect for superconductors with charge-density waves

The nonstationary Josephson I1, interference I2, and quasiparticle J currents through symmmetrical and nonsymmetrical tunnel junctions involving superconductors with charge-density waves (CDW's) were calculated. In the symmetrical (s) case the voltage V dependence of the Josephson current Is1(V) has logarithmic singularities at |eV|=2Δ, Δ+D, and 2D, where D=√((Δ2+Σ2)), Δ is the superconducting order parameter, Σ is the dielectric order parameter, and e is the elementary charge. For temperatures T≠0 the jump at a bias |eV|=D-Δ emerges in Is1(V). The Is2(V) and Js(V) possess jumps and singularities at the same biases where singularities and jumps occur in Is1(V). For the nonsymmetrical (ns) junctions, which include also the ordinary superconductor, singularities and jumps appear at biases |eV|=D+ΔBCS, Δ +ΔBCS, and (for T≠0) |D-ΔBCS| and |Δ-ΔBCS|. Here ΔBCS is the superconducting order parameter of the ordinary superconductor. The quasiparticle current Jns is an asymmetrical function of the voltage V and depends on the sign of Σ. The theory describes the properties of NbSe3 and high-Tc oxides. copyright 1997 The American Physical Society