Bose-Einstein Condensation in Nonlinear System

Bose–Einstein condensation was discovered in atomic gas systems, where Bose condensate occupies 100% of the total system at zero temperature. Liquid helium systems have been investigated based on the Landau theory, where the superfluid component of liquid helium is background flow. According to the Landau theory, it is doubtful that the superfluid component is a Bose condensate. In experiments, th...