Mechanical nanomanipulation of single strain-induced semiconductor quantum dots

We report on low temperatures (4 K) in situ nanomanipulation of the confining potential of single strain-induced Ga0.9In0.1As quantum dots. This was achieved by scanning a metal coated tapered optical fiber tip over the self organized InP stressor islands that are responsible for the localized strain field in the GaInAs/GaAs quantum well. By scanning the tip with a shear force contact of the order of 1 nN, we thinned down the InP stressor islands in an unexpectedly reproducible and controlled way. The modification of the confining potential was directly monitored by measuring in situ the photoluminescence of each manipulated dot using a near-field scanning optical microscope