PHENOMENOLOGICAL THEORY OF 2-DIMENSIONAL QUANTUM LIQUIDS

A phenomenological theory is presented for two-dimensional quantum liq uids in terms of the Fermi surface geometry. It is shown that there is a one-to-one correspondence between the properties of an interacting electron system and its corresponding Fermi surface. By doing this, th e concept of Fermi surface is generalized to include different topolog ies. It is shown that for a Fermi liquid the corresponding Fermi surfa ce is rough. In the presence of a condensate, the Fermi surface is fac eted while, for a ferromagnetic instability, the Fermi surface becomes a frozen solid. I also determine the surface tension, the step free e nergy, low-lying excitations and other surface and transport propertie s of the Fermi surface. The different transitions between these phases are also determined. A non-Fermi-liquid phase is shown to be a pre-ro ugh state of the Fermi surface, the properties of which are briefly an alysed.