Quantum Innovation
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Applying science, engineering, and a study of the challenges faced by individuals and societies to design new technologies that leverage the special behaviour of quantum particles can help to make our world a better place.
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Item A comparative study of the long-term aqueous durability of brannerite (Ce0.94Ti2O6–δ) and glass-brannerite (Fe-Al-BG-Ce0.94Ti2O6–δ) composite materials(Applied Surface Science, 2025-01) Mikhchian, Mehrnaz; Grosvenor, AndrewThe long-term aqueous corrosion behavior of Fe-Al borosilicate glass-brannerite (Fe-Al-BG- Ce0.94Ti2O6–δ) composite material as a potential nuclear wasteform has been investigated to understand how the corrosion behavior of these materials can be compared to current nuclear wasteforms (i.e., borosilicate glass). It was found that the aqueous corrosion behavior of the Fe-Al-BG-Ce0.94Ti2O6–δ composite material resulted from a combined corrosion behavior of the individual Fe-Al-BG and Ce0.94Ti2O6–δ phases when these materials were exposed to deionized water. A combination of surface and bulk analyses has demonstrated that the surface composition and chemistry of Ce0.94Ti2O6–δ and Fe-Al-BG-Ce0.94Ti2O6–δ composite materials were affected by aqueous corrosion, whereas the long-range (i.e., bulk) structure of these materials remained stable over 365 days of exposure to deionized water. This study has shown that the corrosion resistance of Fe-Al-BG-Ce0.94Ti2O6–δ composite material is comparable to Fe-Al-BG, which suggests that this composite material could be further investigated as a potential substitute for borosilicate glass nuclear wasteforms.Item Characterizing Structure and Electrochemical Properties of Advanced Si/C Anode Materials(Journal of The Electrochemical Society, 2025-01) Rathore, Divya; Abraham, Jeffin James; Mendel-Elias, Eytan; Li, Zhifei; Zaker, Nafiseh; Amirkhiz, Babak Shalchi; Michel, Johnson; Hamam, Ines; Leontowich, Adam; Bond, Toby; Dahn, JeffThe increasing commercial interest in silicon-based anode materials for Li-ion batteries has driven the development of advanced structural designs to address the challenges of poor cycling stability. This study examines the structure of commercial silicon/carbon composite materials where nano silicon clusters are embedded within a carbon matrix. The size of silicon and carbon nanoclusters is determined by comparing experimental X-ray diffraction patterns with calculated patterns based on the Debye scattering formalism, as implemented in the program DEBUSSY. The size, morphology, surface areas, and porosities of the carbon matrix and composite are measured, along with their resulting tap and true densities. Their electrochemical performance is also assessed to determine operando stack growth and cycling stability. By restricting silicon cluster sizes to sub-nanometer dimensions within a porous carbon matrix, a low specific surface area can be achieved along with a specific capacity of ∼2000 mAh g−1. Additionally, this approach results in high tap density values close to 1 g cc−1, reduces reversible stack growth, and minimizes irreversible stack growth caused by particle cracking during volume changes, thereby significantly enhancing the overall stability and performance of the anode material.Item The impact of non-uniformity and resistivity on the homogenised corrosion parameters of rebars in concrete – a circuit model analysis(Corrosion Engineering, Science and Technology: The International Journal of Corrosion Processes and Corrosion Control, 2023-06) Li, Gang; Evitts, Richard; Boulfiza, MohWhen rebar corrosion parameters are characterised from an electrochemical polarisation curve, the non-uniform rebar surface conditions need to be considered. In this research, a circuit model was developed to simulate the polarisation behaviour of rebar in concrete. It is found that the resistivity of concrete leads to non-uniform potential on the rebar, which causes the polarisation curve of the entire rebar to deviate from the Butler–Volmer kinetics. This, in turn, leads to an overestimation of the Tafel constants and the corrosion current density. Such deviations are more pronounced with higher concrete resistivity, especially when the active and passive rebar surfaces have a similar area ratio. The study recommends using potentiodynamic scans of representative reinforced concrete samples of the field conditions or the calculated parameters using an averaging technique, such as the proposed circuit model, to obtain accurate E-I curves or parameters for electrochemical modelling and corrosion rate prediction.Item Conditional cross-correlation analysis of floating potential fluctuations in the TJ-II stellarator(Radiation Effects and Defects in Solids, 2024-12-31) Bsharat, H Voldiner, Igor van Milligen, B. Ph Xiao, CThe conditional nonlinear cross-correlation technique has been used to analyze the floating potential fluctuations measured by a radially distributed rake probe array during the electrode biasing experiments on the TJ-II stellarator. Preliminary results suggest that the propagation direction of the turbulence energy changes from outwards in the case without biasing to inwards when biasing is applied.Item Bounds on 𝑎_𝜇^(HVP,LO) using Hölder's inequalities and finite-energy QCD sum rules(Elsevier, 2024-09-26) Li, Siyuan; Steele, Tom; Ho, Jason; R-Rahaman, Raza; Williams, K.; Kleiv, RobinThis study establishes bounds on the leading-order (LO) hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon (𝑎_𝜇^(HVP,LO), 𝑎𝜇 = (𝑔 − 2)𝜇∕2) by using Hölder’s inequality and related inequalities in Finite-Energy QCD sum rules. Considering contributions from light quarks (𝑢, 𝑑, 𝑠) up to five-loop order in perturbation theory within the chiral limit, leading-order light-quark mass corrections, next-to-leading order for dimension-four QCD condensates, and leading-order for dimension-six QCD condensates, the study finds QCD lower and upper bounds as (657.0 ± 34.8) × 10−10 ≤ 𝑎_𝜇^(HVP,LO) ≤ (788.4 ± 41.8) × 10−10.Item Quantum Fibrations: Quantum Computation on an Arbitrary Topological Space(Springer, 2024-07-10) Ikeda, KazukiUsing operator algebras, we extend the theory of quantum computation on a graph to a theory of computation on an arbitrary topological space. Quantum computation is usually implemented on finite discrete sets, and the purpose of this study is to extend this to theories on arbitrary sets. The conventional theory of quantum computers can be viewed as a simplified algebraic geometry theory in which the action of SU(2) is defined on each point of a discrete set. In this study, we extend this in general as a theory of quantum fibrations in which the action of the von Neumann algebra is defined on an arbitrary topological space. The quantum channel is then naturally extended as a net of von Neumann algebras. This allows for a more mathematically rigorous discussion of general theories, including physics and chemistry, which are defined on sets that are not necessarily discrete, from the perspective of quantum computer science.