Nucleation of 2π-phase soliton in charge-density-wave systems

Dynamical nucleation of a 2 pi-phase soliton in clean charge-density-wave (CDW) systems is studied using the Keldysh Green function technique within the quasiclassical approximation. We obtain a self-consistent solution for such dynamical nucleation and find that the 2 pi soliton can be nucleated without a large deviation from the equilibrium quasiparticle distribution. The nucleation induces the local shift delta mu in the chemical potential. It is shown that delta mu is determined by the distortion of the CDW phase outside the soliton core, and the order-parameter variation in the core region is not responsible for delta mu. It is also shown that the magnitude of delta mu is much smaller than a previous estimate.