QUANTUM TUNNELING OF THE DOMAIN-WALL IN A WEAK FERROMAGNET

An investigation of the macroscopic tunneling of the domain wall was p erformed taking into account the nonlinear dependence of the wall velo city versus the external influence. Since the Hamilton function is not quadratic in momentum, the necessary development of the path integral formalism was carried out. An explicit expression for the tunneling r ate was obtained. The instanton trajectory can be calculated analytica lly for any shape of the potential barrier. A comparison was made betw een theory and experiment.