College Physics
Nonlinear Landau-Zener tunnelling
Biao Wu
Abstract
The basic properties of the nonlinear Landau-Zener tunnelling,a new quantum tunnelling phenomenon is reviewed,which is discovered in interacting two-level systems,such as Bose-Einstein condensates in optical lattices and molecule magnets.It is found that the nonlinearity induced by the repulsive interaction can enhance the tunnelling probability compared to the usual linear Landdau-Zener tunnelling.When the nonlinearity is strong enough,the adiabaticity can break down:an infinitely small external linear force can cause finite tunnelling probability.