Optimisation of scalable ion-cavity interfaces for quantum photonic networks
Physical Review Applied American Physical Society 19 (2023) 014033
Abstract:
In the design optimization of ion-cavity interfaces for quantum networking applications, difficulties occur due to the many competing figures of merit and highly interdependent design constraints, many of which present “soft limits,” which are amenable to improvement at the cost of engineering time. In this work, we present a systematic approach to this problem that offers a means to identify efficient and robust operating regimes and to elucidate the trade-offs involved in the design process, allowing engineering efforts to be focused on the most sensitive and critical parameters. We show that in many relevant cases it is possible to approximately separate the geometric aspects of the cooperativity from those associated with the atomic system and the mirror surfaces themselves, greatly simplifying the optimization procedure. Although our approach to optimization can be applied to most operating regimes, here we consider cavities suitable for typical ion-trapping experiments and with substantial transverse misalignment of the mirrors. We find that cavities with mirror misalignments of many micrometers can still offer very high photon extraction efficiencies, offering an appealing route to the scalable production of ion-cavity interfaces for large-scale quantum networks.Effects of cavity birefringence in polarisation-encoded quantum networks
New Journal of Physics IOP Publishing (2022)
Abstract:
<jats:title>Abstract</jats:title> <jats:p>The generation of entanglement between distant atoms via single photons is the basis for networked quantum computing, a promising route to large-scale trapped-ion and trapped-atom processors. Locating the emitter within an optical cavity provides an efficient matter-light interface, but mirror-induced birefringence within the cavity introduces time-dependence to the polarisation of the photons produced. We show that such ‘polarisation oscillation’ effects can lead to severe loss of fidelity in the context of two-photon, polarisation encoded measurement-based remote entanglement schemes. It is always preferable to suppress these errors at source by minimising mirror ellipticity, but we propose two remedies for systems where this cannot be achieved. We conclude that even modest cavity birefringence can be detrimental to remote entanglement performance, to an extent that may limit the suitability of polarisation-encoded schemes for large-scale quantum networks.</jats:p>[Data and analysis] Optimisation of scalable ion-cavity interfaces for quantum photonic networks
University of Oxford (2022)
Abstract:
Numerical data generated from python module available at DOI:10.5281/zenodo.7020047. Data are presented and analysed in arxiv 2112.05795Optimisation of Scalable Ion-Cavity Interfaces for Quantum Photonic Networks
ArXiv 2112.05795 (2021)