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HL: Halbleiterphysik

HL 14: Optische Eigenschaften

HL 14.8: Vortrag

Dienstag, 28. März 2000, 11:15–11:30, H13

The Aharonov-Bohm effect for an exciton — •R.A. Römer¹ and M.E. Raikh² — ¹Institut für Physik, Technische Universität, D-09107 Chemnitz — ²Department of Physics, University of Utah, Salt Lake City, Utah 84112, U.S.A.

We study theoretically the exciton absorption on a ring threaded by a magnetic flux. For the case when the attraction between electron and hole is short-ranged we get an exact solution of the problem. We demonstrate that, despite the electrical neutrality of the exciton, both the spectral position of the exciton peak in the absorption, and the corresponding oscillator strength oscillate with magnetic flux with a period Φ₀—the universal flux quantum. The origin of the effect is the finite probability for electron and hole, created by a photon at the same point, to tunnel in the opposite directions and meet each other on the opposite side of the ring.