Periodic Reporting for period 3 - QUANtIC (Quantum Nanowire Integrated Photonic Circuits)
Período documentado: 2022-01-01 hasta 2023-06-30
One of the most promising candidates for implementing highly efficient emitters and quantum light sources are nanostructured III-V semiconductors. In particular, light sources incorporated in the form of III-V semiconductor nanowires (NW) are emerging as very promising platform due to many extraordinary properties: (i) NWs are natural dielectric resonator cavities providing intrinsically a gain medium for emission of coherent photons while simultaneously acting as optical waveguide, (ii) they can be integrated in a highly deterministic, position-controlled fashion onto Si with very small foot-print while maintaining high structural integrity, (iii) the 1D-structure offers exceptionally high light extraction efficiency and emission directionality from embedded quantum emitters, and (iv) the optical properties can be tuned by strong electronic quantum confinement phenomena.
The objective of this action is to combine the unprecedented features of semiconductor NWs and realize first demonstrations of high-performance classical and non-classical light sources monolithically integrated onto photonic/quantum circuits for on-chip communication and metrology. The ultimate vision of this scalable technology is to enable solid-state optical networks at the emitter-waveguide, emitter-emitter, and emitter-environment interface, where NW-based emitters can be exploited for signal manipulation, distribution, switching and sensing down to the few-photon limit.
Finally, with respect to objectives focusing on non-classical (quantum) light sources integrated onto quantum photonic integrated circuits (QPIC), we proposed new NW-based architectures that embed single quantum dots (QD) as ideal sources for high-brightness single photons, a key ingredient for quantum technological applications in secure data communication and distributed quantum computing. In particular, we demonstrated through numerical simulations how the architecture needs to be tuned for efficient light coupling and propagation of single photons into a SOI-based QPIC. We found that by placing the QD emitter close to the SOI-based WG, peak power coupling efficiencies of up to > 80% can be realized.
Likewise, for vertical-cavity NW-QD emitters coupled to QPIC, we aim to demonstrate experimentally the efficient coupling of deterministic, high-brightness single photons to SOI-based WGs for on-chip quantum communication, as proposed in our numerical simulation studies. Thanks to the excellent scalability of position-control of NW-WG cavities on QPIC this will allow the realization of multi-photon Boson sampling experiments from on-chip QDs. Such on-chip QPIC NW-QD sources will further offer exceptional platform to create spin networks with charged QDs at nodes for on-chip communication via photons, exploiting the transfer of spin information via circular photon states. Here, a central goal is to harness the unique spin-orbit interactions in sub-wavelength QPIC to control the spatial degree of freedom of light and tune intensity distributions and propagation paths of single photons within IQPCs. Thereby, the QD-in-NW-cavity platform will provide a uniquely deterministic approach to study such chiral-light-matter interactions for future spin-based quantum networks, where coupling and photon exchange effects from multiple on-chip QDs will be exploited.