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arXiv · 2301.03541

A unipolar quantum dot diode structure for advanced quantum light sources

T. Strobel·J. H. Weber·M. Schmidt·L. Wagner·L. Engel·M. Jetter·A. D. Wieck·S. L. Portalupi·A. Ludwig·P. Michler
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Abstract

Triggered, indistinguishable, single photons play a central role in various quantum photonic implementations. Here, we realize a novel n$^+-$i$-$n$^{++}$ diode structure embedding semiconductor quantum dots: the gated device enables spectral tuning of the transitions and deterministic control of the observed charged states. Blinking-free single-photon emission and high two-photon indistinguishability is observed. The linewidth's temporal evolution is investigated for timescales spanning more than $6$ orders of magnitude, combining photon-correlation Fourier spectroscopy, high-resolution photoluminescence spectroscopy, and two-photon interference (visibility of $V_{\text{TPI, 2ns}}=\left(85.5\pm2.2\right){\%}$ and $V_{\text{TPI, 9ns}}=\left(78.3\pm3.0\right){\%}$). No spectral diffusion or decoherence on timescales above $\sim 9\,\text{ns}$ is observed for most of the dots, and the emitted photons' linewidth $\left(\left(420\pm30\right)\text{MHz}\right)$ deviates from the Fourier-transform limit only by a factor of $1.68$. Thus, for remote TPI experiments, visibilities above $74\%$ are anticipated. The presence of n-doping only signifies higher available carrier mobility, making the presented device highly attractive for future development of high-speed tunable, high-performance quantum light sources.

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T. Strobel, J. H. Weber, M. Schmidt, L. Wagner, L. Engel, M. Jetter, A. D. Wieck, S. L. Portalupi, A. Ludwig, P. Michler. 2023-01-09. A unipolar quantum dot diode structure for advanced quantum light sources. https://doi.org/10.1021/acs.nanolett.3c01658

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