Abstract

Among the most promising ways to achieve the goal of fabricating one-dimensional quantum structures such as quantum wires and zero-dimensional quantum structures such as quantum dots at the same degree of perfection achieved in the two-dimensional quantum systems (quantum wells) is cleaved edge overgrowth (CE O).^1–2 We report on the first low temperature near-field scanning optical microscopy study of a single, nanometer dimension, cleaved edge overgrown quantum wire fabricated by this technique. A direct experimental comparison between a two-dimensional system and a single genuinely one-dimensional quantum wire system, inaccessible to conventional far-field optical spectroscopy, is enabled by enhanced spatial resolution. We show that the photoluminescence of a single quantum wire is distinguished easily from that of the surrounding quantum well. Emission from localized centers is shown to dominate the photoluminescence of both wires and wells at low temperatures. A factor of three absorption enhancement in the CEO wires compared with that in the CEO wells is concluded from the photoluminescence excitation data. This is in good agreement with the theoretical prediction.³

© 1996 Optical Society of America