FRACTIONAL QUANTUM HALL-EFFECT IN A 2-DIMENSIONAL ELECTRON-HOLE FLUID

We show that a two-dimensional electron-hole fluid in a strong perpendicular magnetic field has a quantized Hall conductance equal to e2c/h at certain values of c, where c=e-h and e and h are the electron and hole filling factors. The ground states responsible for the quantized Hall effect consist of an incompressible fluid of excess charges and a Bose-condensed gas of excitons which do not interact either with each other or with the excess charge fluid. These results follow from an exact mapping between the electron-hole system and a two-component electron system. © 1990 The American Physical Society.