Two-dimensional one-component plasma in a quadrupolar field

The classical two-dimensional one-component plasma is an exactly solvable model, at some special temperature, even when the one-body potential acting on the particles has a quadrupolar term. As a supplement to a recent work of Di Francesco, Gaudin, Itzykson, and Lesage [{\it Int. J. Mod. Phys.} {\bf A9}, 4257 (1994)] about an $N$-particle system ($N$ large but finite), a macroscopic argument is given for confirming that the particles form an elliptical blob, the analogy between the classical plasma and a quantum $N$-fermion system in a magnetic field is used for the microscopic approach, and a microscopic calculation of the surface charge-surface charge correlation function is performed; an expected universal form is shown to be realized by this correlation function.