Strongly Correlated Coulomb Liquid

Abstract

In typical liquids and even solids, the average interaction potential energy per particle is approximately of the same order of magnitude as the average kinetic energy. Under these conditions, the Fermi liquid approach, which reduces the many-body system of strongly interacting particles to the system of weakly interacting excitations, has proven to be quite effective. On the other hand, the Coulomb liquid is characterized by extremely strong internal forces acting between electrons. This makes the conventional quasi-particle approach doubtful. As emphasized above, in the 2D Coulomb liquid of interface electrons the average interaction potential energy per electron can be approximately a hundred times larger than the average kinetic energy. One cannot rely on the Fermi liquid approach under such extreme conditions. It is even impossible to introduce a definite excitation spectrum valid for the whole Coulomb liquid if the system is subject to a normal magnetic field.