Quantum fluctuations of solitons in two-dimensional anisotropic σ models

We study quantum fluctuations about static soliton solutions for the two-dimensional anisotropic {σ} models. Particularly, for the XY-like anisotropy, we find that quantum corrections induce an internal degree of freedom and lower the soliton's classical energy. For Ising-like anisotropy, quantum corrections raise the classical energy of the soliton. In both cases, the corrections are proportional to the anisotropy parameter and depend on the size of the soliton.