Superfluidity of indirect magnetoexcitons in coupled quantum wells

The temperature T-c of the Kosterlitz-Thouless transition to a superfluid state for a system of magnetoexcitons with spatially separated electrons e and holes h in coupled quantum wells is obtained as a function of magnetic field H and interlayer separation D. It is found that T-c decreases as a function of H and D at fixed exciton density n(ex) as a result of an increase in the exciton magnetic mass. The highest Kosterlitz-Thouless transition temperature as a function of H increases (at small D) on account of an increase in the maximum magnetoexciton density n(ex) versus magnetic field, where n(ex) is determined by a competition between the magnetoexciton energy and the sum of the activation energies of incompressible Laughlin fluids of electrons and holes. (C) 1997 American Institute of Physics.