Strain-induced tuning of the emission wavelength of high quality GaAs/AlGaAs quantum dots in the spectral range of the ⁸⁷Rb D₂ lines

Reversible biaxial strains are used for tuning the emission wavelengths of high quality GaAs/AlGaAs quantum dots (QDs) in the spectral range of the ⁸⁷Rb D₂ lines. The strain is transferred by integrating free standing (Al)GaAs nanomembranes, containing QDs, onto piezoelectric actuators. Narrow excitonic emission lines as sharp as 25 μeV are shown, and a tuning range larger than 5 nm is demonstrated. This range corresponds to an induced anisotropic biaxial strain of the order of 0.15%, as evaluated from the shift in the emission of the GaAs from the nanomembranes. The presented on-chip technology is potentially interesting for future quantum memories based on hybrid semiconductor-atomic interfaces.