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SYPQ: High Yield Devices for Photonic Quantum Implementations

SYPQ 1: High Yield Devices for Photonic Quantum Implementations

SYPQ 1.2: Hauptvortrag

Dienstag, 6. September 2022, 10:00–10:30, H1

Challenges towards high efficiency quantum dot single photon sources — •Arne Ludwig — Ruhr-Universität Bochum, Germany

A key component for photonic quantum devices is a source of high-fidelity photonic qubits, a single photon source (SPS) [1]. A promising route to create such a device employs semiconductor quantum dots (QDs) in photonic cavities. These approaches exploit the exquisite toolbox of semiconductors, in particular scalable manufacturing.

However, noise processes hampering these [2]. A main contributor to decoherence and low efficiency is random charge rearrangements in the semiconductor environment or the QD itself. A random change of the QD charge state from e.g. Auger processes [3] or photoionization [4] can switch the emitter temporarily off [3,5].

Noise from a fluctuating electrostatic environment is called charge noise. One way to efficiently suppress this, is to embed the QDs in the high purity material undoped region of a p-i-n-diode [6,7]. This approach combined with a tuneable cavity has been pursued to realize a highly efficient fiber-coupled SPS with an end-to-end efficiency of 57% [8].

[1] P. Senellart et al., Nat Nano 12, 1026 (2017). [2] A.V. Kuhlmann et al., Nat Phys 9, 570 (2013). [3] A. Kurzmann et al., Nano Lett 16, 3367 (2016). [4] P. Lochner et al., Phys. Rev. B 103, 075426 (2021). [5] G. Gillard et al., npj Q Inf 7, 43 (2021). [6] D. Najer et al., Nature 575, 622 (2019). [7] L. Zhai et al., Nat Commun 11, 4745 (2020). [8] N. Tomm et al., Nat Nano 16, 399 (2021).