MAGNETIC TRAP FOR EXCITONS

High in-plane magnetic held gradients are used to control the lateral motion of excitons in an InGaAs quantum well. The gradients, as large as 6.10(4) T/m, are produced by positioning a thin magnetized stripe o f dysprosium on top of the quantum well. By measuring the exciton phot oluminescence energy and intensity, spatially resolved with um resolut ion, it is shown that the diamagnetic excitons are forced to regions o f low magnetic field, because of the interaction of their magnetic mom ent with the inhomogeneous field. These results show the possibility t o magnetically confine excitons to a limited region of space, which op ens the way for the realization of the first magnetic trap in solids. (C) 1998 Elsevier Science B.V. All rights reserved.