Laser spectroscopy of individual quantum dots charged with a single hole

TL;DR

This study uses resonant laser spectroscopy to analyze positively charged excitons in single InGaAs quantum dots with different dopants, revealing dopant-dependent optical properties and potential for single hole spin control.

Contribution

It provides a comparative analysis of dopant effects on quantum dot optical properties and demonstrates a device structure suitable for single hole spin manipulation.

Findings

C-doped quantum dots show isolated atomic transition behavior

Be-doped samples exhibit Fano coupling effects

C-doped devices are promising for hole spin control

Abstract

We characterize the positively charged exciton (X1+) in single InGaAs quantum dots using resonant laser spectroscopy. Three samples with different dopant species (Be or C as acceptors, Si as a donor) are compared. The p-doped samples exhibit larger inhomogeneous broadening (x3) and smaller absorption contrast (x10) than the n-doped sample. For X1+ in the Be-doped sample, a dot dependent non-linear Fano effect is observed, demonstrating coupling to degenerate continuum states. However, for the C-doped sample the X1+ lineshape and saturation broadening follows isolated atomic transition behaviour. This C-doped device structure is useful for single hole spin initialization, manipulation, and measurement.