VCQ Colloquium by Klaus Jöns, Paderborn University

30.11.2020 17:00 - 18:30

"Hybrid quantum photonic devices"


I will present our recent results on hybrid quantum photonic devices as building blocks for integrated photonic quantum technologies, as shown schematically in figure 1. The hybrid approach allows us to harvest synergy effects between previously independent research fields, providing new functionalities and insights in the fascinating world of photonic quantum sciences. I will first introduce solid-state quantum emitters, their unique properties, as well as some of their advantages and remaining challenges. Afterwards I will discuss our approach to integrate quantum light sources in complex on-chip quantum circuits. Currently, the most promising on-demand single photon sources are based on III/V semiconductor quantum dots [1]. However, complex photonic circuitry is mainly achieved in silicon photonics due to the tremendous technological challenges in circuit fabrication. We take the best of both worlds by developing a hybrid nanofabrication technique [2], allowing to integrate III/V semiconductor nanowire quantum dots [3] into silicon-based photonics. I will present on-chip generation, spectral filtering, and routing of single-photons from selected single and multiple quantum emitters all deterministically integrated in a CMOS compatible silicon nitride photonic circuit [4]. Furthermore, I will introduce a heterogeneous integration of micro-electromechanical systems with superconducting single photon detectors as an alternative active circuit element for quantum photonic integrated circuits [5]. In the second part I will discuss our efforts to fabricate large-scale quantum photonic integrated circuits using 2D materials as the on-chip quantum light source. 2D materials such as WSe2 have gotten substantial attention after the discovery of single-photon emission and are currently widely explored as novel quantum emitters. On the one hand, we take advantage of the strain-induced creation of these quantum emitters to couple single photons to photonic circuits [6]. On the other hand, a new technique using He-ion bombardment of MoS2 enables the deterministic creation of single photon sources with unprecedented position accuracy [7]. Our approaches eliminate the need for off-chip components, opening up new possibilities for largescale quantum photonic devices with different kinds of on-chip single- and entangled-photon sources.



[1] L. Schweickert et al., Appl. Phys. Lett. 112, 093106 (2018).

[2] I. Esmaeil Zadeh et al., Nano Letters 16(4), 2289-2294 (2016).

[3] M. A. M. Versteegh et al., Nature Communications 5, 5298 (2014).

[4] A. W. Elshaari et al., Nature Communications 8, 379 (2017).

[5] S. Gyger et al., arXiv:2007.06429 (2020).

[6] C. Errando Herranz et al., arXiv:2002.07657 (2020).

[7] J. Klein et al., arXiv:2002.08819 (2020) and K. Barthelmi et al., Appl. Phys. Lett. 117, 070501 (2020).



Host: Karl Unterrainer


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