Strain-gradient mapping of semiconductor quantum dots

TL;DR

This paper introduces a non-destructive method to precisely map the positions of semiconductor quantum dots within a solid waveguide by exploiting stress-induced frequency shifts, advancing quantum microscopy capabilities.

Contribution

The work presents a novel technique using oscillating stress gradients to accurately locate quantum dots embedded in solid photonic structures, which was not previously achieved.

Findings

Achieved position accuracy from +/- 35 nm to +/- 1 nm.

Demonstrated non-destructive quantum dot mapping.

Applicable to deeply embedded quantum dots in solid structures.

Abstract

In the context of fast developing quantum technologies, locating single quantum objects embedded in solid or fluid environment while keeping their properties unchanged is a crucial requirement as well as a challenge. Such "quantum microscopes" have been demonstrated already for NV-centers embedded in diamond [1], and for single atoms within an ultracold gas [2]. In this work, we demonstrate a new method to determine non-destructively the position of randomly distributed semiconductor quantum dots (QDs) deeply embedded in a solid photonic waveguide. By setting the wire in an oscillating motion, we generate large stress gradients across the QDs plane. We then exploit the fact that the QDs emission frequency is highly sensitive to the local material stress [3-5] to infer their positions with an accuracy ranging from +/- 35 nm down to +/-1 nm for close-to-axis QDs.