VORTICES AND VORTICAL STRUCTURES IN SYSTEMS WITH PAIRING OF SPATIALLYSEPARATED ELECTRONS AND HOLES

The properties of systems with pairing of spatially separated electron s and holes are studied below the superconducting transition temperatu re T-c. Another phenomenon in these systems is predicted. It is shown that in certain nonuniform magnetic fields the planar vortices in whic h the electron-hole pairs rotate as a whole in the plane of the struct ure become energy advantageous. Although the planar vortices resemble Onsager-Feynman and Abrikosov vortices, they must form a structure fun damentally different from the one the above vortices form. This struct ure is ordered but noninvariant under translation. In the absence of a magnetic field planar vortices appear in the system due to thermal fl uctuations. The velocity field of a planar vortex decreases inversely with the distance to the vortex center. This leads to a pairing of the rmally excited vortices with the opposite circulations at the temperat ures below T-c.