Interfacial deep-level defects as probes for ultrathin InAs insertions in GaAs

Due to their short-range potential, interfacial deep-level defects can be a pplied as local probes for the lateral confinement of quantum states in zer o-dimensional structures. Single, ultrathin InAs insertions in GaAs are inv estigated by deep-level transient Fourier spectroscopy and capacitance-volt age measurements. It is experimentally verified that the large number of sm all, highly strained InAs islands, which are formed near the transition fro m layer-by-layer to three-dimensional growth, results in quantum states, wh ich are laterally confined across the plane of the ultrathin InAs insertion in GaAs. (C) 1999 Elsevier Science B.V. All rights reserved.