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arXiv · 1708.00520

Narrow optical linewidths and spin pumping on charge-tunable, close-to-surface self-assembled quantum dots in an ultra-thin diode

Matthias C. Löbl·Immo Söllner·Alisa Javadi·Tommaso Pregnolato·Rüdiger Schott·Leonardo Midolo·Andreas V. Kuhlmann·Søren Stobbe·Andreas D. Wieck·Peter Lodahl·Arne Ludwig·Richard J. Warburton
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Abstract

We demonstrate full charge control, narrow optical linewidths, and optical spin pumping on single self-assembled InGaAs quantum dots embedded in a $162.5\,\text{nm}$ thin diode structure. The quantum dots are just $88\,\text{nm}$ from the top GaAs surface. We design and realize a p-i-n-i-n diode that allows single-electron charging of the quantum dots at close-to-zero applied bias. In operation, the current flow through the device is extremely small resulting in low noise. In resonance fluorescence, we measure optical linewidths below $2\,μ\text{eV}$, just a factor of two above the transform limit. Clear optical spin pumping is observed in a magnetic field of $0.5\,\text{T}$ in the Faraday geometry. We present this design as ideal for securing the advantages of self-assembled quantum dots -- highly coherent single photon generation, ultra-fast optical spin manipulation -- in the thin diodes required in quantum nano-photonics and nano-phononics applications.

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Matthias C. Löbl, Immo Söllner, Alisa Javadi, Tommaso Pregnolato, Rüdiger Schott, Leonardo Midolo, Andreas V. Kuhlmann, Søren Stobbe, Andreas D. Wieck, Peter Lodahl, Arne Ludwig, Richard J. Warburton. 2020-10-08. Narrow optical linewidths and spin pumping on charge-tunable, close-to-surface self-assembled quantum dots in an ultra-thin diode. https://doi.org/10.1103/physrevb.96.165440

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