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Thomas Wood

Publications and source records attributed to Thomas Wood.

4 recordsLinked to original sources

Autonomous battery research: Principles of heuristic operando experimentation

Unravelling the complex processes governing battery degradation is critical to the energy transition, yet the efficacy of operando characterisation is severely constrained by a lack of Reliability, Representativeness, and Reproducibility (the 3Rs). Current methods rely on bespoke hardware and passive, pre-programmed methodologies that are ill-equipped to capture stochastic failure events. Here, using the Rutherford Appleton Laboratory's multi-modal toolkit as a case study, we expose the systemic inability of conventional experiments to capture transient phenomena like dendrite initiation. To address this, we propose Heuristic Operando experiments: a framework where an AI pilot leverages physics-based digital twins to actively steer the beamline to predict and deterministically capture these rare events. Distinct from uncertainty-driven active learning, this proactive search anticipates failure precursors, redefining experimental efficiency via an entropy-based metric that prioritises scientific insight per photon, neutron, or muon. By focusing measurements only on mechanistically decisive moments, this framework simultaneously mitigates beam damage and drastically reduces data redundancy. When integrated with FAIR data principles, this approach serves as a blueprint for the trusted autonomous battery laboratories of the future.

physics.ins-det

Molecular dynamics simulation of W Silicon Emitting Centers formation by Ga ion implantation

Silicon Emitting Centers (SEC) constitute promising candidates for quantum telecommunication technologies. Their operation depends on the fabrication of light emitting defect centers such as the triinterstitial Si complex, the W-Center. In this paper the formation of Si tri-interstitial clusters after Ga ion beam bombardment on pure silicon substrates and a subsequent annealing stage is investigated using molecular dynamics (MD) simulations. This study aims to understand the dynamic formation process of W centers after Ga implantation and annealing in order to assist the focused ion beam and annealing experimental systems. A new tri-interstitial cluster identification method is proposed which considers the configuration of the clusters in the Si lattice in order to identify the defects which will act as candidates for the W center. This method successfully identifies W center defect candidates in an ideal system. The number of tri-interstitial clusters increases and spread deeper into the Si for higher energies and their probability of generation increases until a limiting Ga dose. Furthermore, annealing can eliminate a lot of the unwanted defects maintaining at the same time the number of the tri-interstitial clusters, leading to isolated clusters with less distorted local environment.

cond-mat.mtrl-sci

Femtosecond laser induced creation of G and W-centers in silicon-on-insulator substrates

The creation of fluorescent defects in silicon is a key stepping stone towards assuring the integration perspectives of quantum photonic devices into existing technologies. Here we demonstrate the creation, by femtosecond laser annealing, of W and G-centers in commercial silicon on insulator (SOI) previously implanted with 12C+ ions. Their quality is comparable to that found for the same emitters obtained with conventional implant processes; as quantified by the photoluminescence radiative lifetime, the broadening of their zero-phonon line (ZPL) and the evolution of these quantities with temperature. In addition to this, we show that both defects can be created without carbon implantation and that we can erase the G-centers by annealing while enhancing the W-centers' emission. These demonstrations are relevant to the deterministic and operando generation of quantum emitters in silicon.

physics.optics

Titania-Based Spherical Mie Resonators Elaborated by High-Throughput Aerosol Spray: Single Object Investigation

In the framework of photonics with all-dielectric nanoantennas, sub-micro-metric spheres can be exploited for a plethora of applications including vanishing back-scattering, enhanced directivity of a light emitter, beam steering, and large Purcell factors. Here, the potential of a high-throughput fabrication method based on aerosol-spray is shown to form quasi-perfect sub-micrometric spheres of polycrystalline TiO 2 . Spectroscopic investigation of light scattering from individual particles reveals sharp resonances in agreement with Mie theory, neat structural colors, and a high directivity. Owing to the high permittivity and lossless material in use, this method opens the way toward the implementation of isotropic meta-materials and forward-directional sources with magnetic responses at visible and near-UV frequencies, not accessible with conventional Si- and Ge-based Mie resonators.

physics.optics