Buried Stressor Engineering for Position-Controlled InGaAs Quantum Dots with Local Density Variation for Integrated...

Area of Science:

• Materials Science
• Quantum Physics
• Nanotechnology

Background:

• Site-controlled quantum dots are crucial for scalable quantum photonic applications.
• Existing methods for quantum dot fabrication often lack precision in placement and density control.

Purpose of the Study:

• To demonstrate a monolithic, two-step epitaxial growth technique for site-controlled InGaAs quantum dots using a buried-stressor method.
• To achieve local variation in quantum dot density with high fabrication accuracy.

Main Methods:

• Utilized a buried-stressor method for site-controlled epitaxy of InGaAs quantum dots.
• Employed microphotoluminescence and cathodoluminescence for characterization.
• Performed theoretical calculations to understand stressor aperture effects.

Main Results:

• Achieved low lateral displacements (${17}_{-17}^{+19}\mathrm{nm}$) of apertures from mesa centers.
• Demonstrated reproducible nucleation of low- and high-density quantum dots within a single growth step.
• Validated the effect of stressor aperture on quantum dot properties via theoretical calculations.

Conclusions:

• The buried-stressor method offers high precision for fabricating site-controlled quantum dots.
• This technique enables the integration of varying quantum dot densities on a single chip.
• Paves the way for advanced photonic quantum technology modules, including single-photon sources and microlasers.