Collective Mode in a Superconductor with Mixed-Symmetry Order Parameter Components

We consider a superconducting state with mixed-symmetry order parameter components, e.g., d+is or d+id' with d'=dxy . We argue for the existence of a new orbital magnetization mode which corresponds to oscillations of relative phase φ between two components around an equilibrium value of φ=(π/2) . It is similar to the ''clapping'' mode in superfluid 3He- A . We estimate the frequency of this mode ω0(B, T) depending on the field and temperature for the specific case of magnetic field induced d'=dxy state. This mode is tunable with a magnetic field with ω0(B, T)∝BΔ0 , where Δ0 is the magnitude of the d -wave order parameter. We also estimate the velocity s(B, T) of this mode. (c) 2000 The American Physical Society