Nonlinear quantum magnetotransport in a strongly correlated two-dimensional electron liquid

Experimental and theoretical studies of nonlinear quantum magnetotransport of a nondegenerate two-dimensional electron liquid formed on the surface of liquid helium are reported. Measurements of the magnetoconductivity as a function of the input voltage are done using the edge magnetoplasmon (EMP) damping method. A nonlinear theory based on the many-electron self-consistent Born approximation (SCBA) is introduced to explain the data. It is shown that the nonlinear decrease of (Formula presented) observed at strong magnetic fields (Formula presented) is due to the cold quantum nonlinear effect caused by the peaked structure of the electron density of states. At weak fields (Formula presented) the heating effect competes with this effect and become of the same magnitude. The magnetic field dependence of the nonlinear narrowing of the EMP damping is in good agreement with the nonlinear many-electron SCBA.