Building a fault-tolerant quantum computer will require vast numbers of physical qubits. For qubit technologies based on solid state electronic devices, integrating millions of qubits in a single processor will require device fabrication to reach a scale comparable to that of the modern CMOS industry. Equally importantly, the scale of cryogenic device testing must keep pace to enable efficient device screening and to improve statistical metrics like qubit yield and voltage variation. Spin qubits based on electrons in Si have shown impressive control fidelities but have historically been challenged by yield and process variation. Here we present a testing process using a cryogenic 300 mm wafer prober to collect high-volume data on the performance of hundreds of industry-manufactured spin qubit devices at 1.6 K. This testing method provides fast feedback to enable optimization of the CMOS-compatible fabrication process, leading to high yield and low process variation. Using this system, we automate measurements of the operating point of spin qubits and probe the transitions of single electrons across full wafers. We analyze the random variation in single-electron operating voltages and find that the optimized fabrication process leads to low levels of disorder at the 300 mm scale. Together these results demonstrate the advances that can be achieved through the application of CMOS industry techniques to the fabrication and measurement of spin qubit devices.

Objective: The aim of this study was to allow researchers to evaluate the Periotest device as a reproducible tool that can be trusted to carry out accurately reproducible and comparable tooth mobility readings. Methods: A reproducibility test was initially conducted taking Periotest recordings for #16 every 10 min with 1 min intervals. Each time, three readings were recorded, and the average of the three was noted. This was followed by recordings for three different subject groups varying in age that were seen three times in 4 weeks, with 2-week intervals between each appointment; recordings were taken of #11, #13 and #16. Nonparametric analysis using the Wilcoxon signed-rank test was carried out. Results: For the reproducibility test, the values of all three readings for each recording session were either exactly the same or differed by up to ±2 Periotest value units. p-value results in the three patient groups showed no significant difference in Periotest values between appointments, with the minor exception of #16 in all three groups, but this was well within the limits of error of the device. Conclusions: Analysis of the Periotest readings in this study indicates that positive (higher) Periotest values correspond to increased tooth mobility.

Intel's efforts to build a practical quantum computer are focused on developing a scalable spin-qubit platform leveraging industrial high-volume semiconductor manufacturing expertise and 300 mm fabrication infrastructure. Here, we provide an overview of the design, fabrication, and demonstration of a new customized quantum test chip, which contains 12-quantum-dot spin-qubit linear arrays, code named Tunnel Falls. These devices are fabricated using immersion and extreme ultraviolet lithography (EUV), along with other standard high-volume manufacturing (HVM) processes as well as production-level process control. We present key device features and fabrication details as well as qubit characterization results confirming device functionality. These results corroborate our fabrication methods and are a crucial step toward scaling of extensible 2D qubit array schemes.

The aim of this study is to examine and evaluate physiologic tooth mobility and movement in different groups of patients. Four groups of patients were examined and recordings were taken. Group A1 consisted of 12 undergraduate students under the age of 30, A2 consisted of 11 members of staff over the age of 30 and A3 consisted of 9 patients with periodontal disease between the ages of 40-65 years old. The fourth Group B, 14 patients between 30-70 years old, received single-tooth restorations and recordings were taken immediately after, a month and four months following the cementation of the restoration. Patients in the first 3 groups showed no significant change in tooth mobility and movement between appointments. The fourth group demonstrated a non-statistically significant increase in tooth mobility following the cementation of the restoration due to the force applied on the occlusal surface of the tooth during the cementation process, while tooth movement was not observed beyond that of physiological tooth migration. Regardless of the age or the restorations a patient receives over the years, with careful occlusal consideration, no significant changes in tooth mobility and movement should be observed.

Elizabeth Dianne Rekow, BSME, MSME, MBA, DDS, MS, Certificate in Orthodontics, and PhD (1944–2022), was a dental science futurist pursuing brave new paths during her career. She was one of the pivotal scientists who initiated the CAD/CAM movement in the 1980s and went on to focus on digital dentistry for the rest of her career. Her professional contributions involved seven patents, 92 peer-reviewed publications, 10 book contributions, 31 proceeding contributions, and well over 100 national and international presentations. She was an avid supporter of women in science. Her greatest contribution was her expansive imagination. She served as 35th president of the American Association for Dental, Oral, and Craniofacial Research in 2006–2007 and 88th president of the International Association for Dental Research in 2011–2012. The present article reviews key elements of her career and includes testimonies from friends about her special relationships.

We model an impact on quantum buried Si/SiGe channel devices from a low ~ 1e11 cm -2 level of defect densities on semiconductor/dielectric interfaces. We discuss a limitation that spurious dot formation sets on qubit gate operations and the impact of defects on voltage-dependent noise and two-qubit (2Q) gate fidelity. We show that classical device engineering schemes via scaling pitch, dielectric thickness, using deeper SiGe buffers, and screening gates allow to mitigate the impact of defects on quantum performance.

Full-scale quantum computers require the integration of millions of quantum bits. The promise of leveraging industrial semiconductor manufacturing to meet this requirement has fueled the pursuit of quantum computing in silicon quantum dots. However, to date, their fabrication has relied on electron-beam lithography and, with few exceptions, on academic style lift-off processes. Although these fabrication techniques offer process flexibility, they suffer from low yield and poor uniformity. An important question is whether the processing conditions developed in the manufacturing fab environment to enable high yield, throughput, and uniformity of transistors are suitable for quantum dot arrays and do not compromise the delicate qubit properties. Here, we demonstrate quantum dots hosted at a 28Si/28SiO2 interface, fabricated in a 300 mm semiconductor manufacturing facility using all-optical lithography and fully industrial processing. As a result, we achieve nanoscale gate patterns with remarkable homogeneity. The quantum dots are well-behaved in the multi-electron regime, with excellent tunnel barrier control, a crucial feature for fault-tolerant two-qubit gates. Single-spin qubit operation using magnetic resonance reveals relaxation times of over 1 s at 1 Tesla and coherence times of over 3 ms, matching the quality of silicon spin qubits reported to date. The feasibility of high-quality qubits made with fully-industrial techniques strongly enhances the prospects of a large-scale quantum computer

Objectives: To investigate the potential mineralising effects of calcium silicate-based den-tine replacement material (BiodentineTM) in comparison with glass-ionomer cement (GIC) (Fuji IXTM) on different human dentine substrates using a multimodal non-invasive optical assessment.Methods: Cements were applied on artificially demineralised or naturally carious dentine and stored for 4 weeks in phosphate-rich media +/-tetracycline used for mineralisation labelling. Interfacial dentine was examined from the same sample and location before and after aging using two-photon fluorescence microscopy, fluorescence lifetime imaging (FLIM) and second harmonic generation (SHG) imaging. Additionally, Raman spectroscopy was used to detect changes in the mineral content of dentine. Results: Significant changes in the fluorescence intensity and lifetime were detected in partially demineralised dentine and caries-affected dentine underneath both tested ce-ments, after storage (p < 0.001). This was associated with a significant increase in the mineral content as indicated by the increased intensity of the phosphate Raman peak lo-cated at 959 cm-1 (p < 0.0001). Caries-infected dentine showed significant fluorescence changes under BiodentineTM after storage (p < 0.001), but not under GIC (p = 0.44). Tetracycline binding induced a reduction in the fluorescence lifetime with comparable increase in the fluorescence intensity in both cements' groups within the affected dentine (p < 0.001). SignificanceTwo-photon fluorescence microscopy can be used efficiently for non-destructive in-vitro dentine caries characterisation providing a technique for studying the same dentine -ce-ment interface over time and detect changes. BiodentineTM demonstrated comparable re -mineralising potential to GIC, in addition to inducing remineralisation of caries-infected dentine. This may suggest using BiodentineTM as part of minimally invasive operative dentistry (MID) in caries management.Crown Copyright (c) 2022 Published by Elsevier Inc. on behalf of The Academy of Dental Materials. All rights reserved.

Objectives: The aim of this study was to evaluate the influence on MMP inhibition, dentin adhesion and physicochemical properties of an adhesive system incorporated with poly-merizable collagen crosslinker monomer derived from cardanol.Methods: The intermediary cardanol epoxy (CNE) was synthesized through cardanol epoxidation, followed by synthesis of cardanol methacrylate through methacrylic acid solvent-free esterification. Zymographic analysis was performed to evaluate the sub-stances' ability to inhibit gelatinolytic enzymes. Collagen crosslinkers were added into adhesives systems according to the following groups: Ybond Universal (R) (Control), Ybond (R) + 2 % proanthocyanidin (PAC), Ybond (R) + 2 % unsaturated cardanol (Cardanol) and Ybond (R) + 2 % cardanol methacrylate (CNMA). Degree of conversion (DC) of the adhesives was as-sessed by FT-IR. Disk-shaped specimens were prepared for water sorption (WS) and solu-bility (SL) tests. Human third molars were sectioned to expose medium dentin and restored according to the different adhesives used (n = 5). Then, the specimens were cut into 1 mm2 sticks to evaluate, after 24 h and 6-month aging, microtensile bond strength (mu TBS) and nanoleakage by scanning electron microscopy. Data were analysed with ANOVA and Tukey's post-test (alpha = 0.05).Results: CNMA and PAC completely inhibited all forms of gelatinolytic enzymes. Cardanol achieved a significantly lowest DC, while the other groups did not differ from each other (p > 0.05). PAC achieved significantly higher water sorption, while CNMA solubility was significantly lower when compared to the other adhesives (p < 0.05). PAC provided a statistically higher 24 h and 6-month aging bond strength. Intermediary similar mu TBS were presented by control and CNMA (p = 0.108). All adhesives applied attained significantly reduced bond strength after aging (p < 0.05). Interfaces created using CNMA were almost devoid of silver deposits initially, however all groups showed large amounts of silver de-posits on resin-dentin interface subjected to water aging.Significance: Although CNMA was effective in inhibiting gelatinolytic enzymes, when in-corporated into a universal adhesive it could not promote less degradation of the adhesive interface after water aging. Since it is a hydrophobic monomer, CNMA did not interact well with dentin collagen, however it reduced the solubility of the adhesive system besides not interfering in its polymerization.(c) 2022 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

We discuss the engineering and physics of both Si MOS and Si/SiGe quantum well based spin qubit devices fabricated in a process compatible with CMOS high volume manufacturing. This includes new process innovations around buffer engineering, EUV lithography for gate pitch scaling, and the creation of a fully electrostatically defined planar quantum dot flow not requiring STI for confinement. Charge sensing, tunnel coupling, and valley splitting are characterized down to the single electron limit for both systems. The gate dielectric interface quality is correlated to potential landscape control and spurious dot formation. While coherent control of spin is demonstrated in both systems with comparable gate fidelity (>99.1%) and coherence times (> 1ms), the scaling challenges are very different, with Si MOS requiring dielectric interface Dit improvements for spurious dot reduction and the Si/SiGe system requiring improvements to valley splitting.

We study spatial noise correlations in a Si/SiGe two-qubit device with integrated micromagnets. Our method relies on the concept of decoherence-free subspaces, whereby we measure the coherence time for two different Bell states, designed to be sensitive only to either correlated or anti-correlated noise respectively. From these measurements, we find weak correlations in low-frequency noise acting on the two qubits, while no correlations could be detected in high-frequency noise. A theoretical model and numerical simulations give further insight into the additive effect of multiple independent (anti-)correlated noise sources with an asymmetric effect on the two qubits. Such a scenario is plausible given the data and our understanding of the physics of this system. This work is highly relevant for the design of optimized quantum error correction codes for spin qubits in quantum dot arrays, as well as for optimizing the design of future quantum dot arrays.

Quantum error correction is of crucial importance for fault-tolerant quantum computers. As an essential step toward the implementation of quantum error-correcting codes, quantum nondemolition measurements are needed to efficiently detect the state of a logical qubit without destroying it. Here we implement quantum nondemolition measurements in a Si/SiGe two-qubit system, with one qubit serving as the logical qubit and the other serving as the ancilla. Making use of a two-qubit controlled-rotation gate, the state of the logical qubit is mapped onto the ancilla, followed by a destructive readout of the ancilla. Repeating this procedure enhances the logical readout fidelity from 75.5±0.3% to 94.5±0.2% after 15 ancilla readouts. In addition, we compare the conventional thresholding method with an improved signal processing method called soft decoding that makes use of analog information in the readout signal to better estimate the state of the logical qubit. We demonstrate that soft decoding leads to a significant reduction in the required number of repetitions when the readout errors become limited by Gaussian noise, for instance, in the case of readouts with a low signal-to-noise ratio. These results pave the way for the implementation of quantum error correction with spin qubits in silicon.

BACKGROUND:The aim of this longitudinal, one-year cohort study was to explore the hypothesis that fluorescence sampling of the root canal space prior to obturation could predict the outcome of root canal treatment (RCT).METHODS:Sixty-five teeth underwent primary RCT and were followed up clinically and radiographically. The outcome was determined radiographically with periapical radiographs (PR) and cone beam computed tomography (CBCT) scans.RESULTS:Success at 12 months was predictable based on the fluorescence score. When the fluorescence score (defined as the percentage of signal over total signal including background) was lower than 67, there was a 4.5 times (Odds ratio (OR) = 0.028; 95% confidence interval (CI): 0.003, 0.291, p = 0.001) greater chance of success (90% overall). When the readings were above this threshold, the success rate was 20%.CONCLUSION:A chairside sampling method is able to predict the outcome of RCT, through the use of paper point sampling and fluorescence staining. This has reduced the prevalence of persistent infections by guiding the optimum time for obturation. ClinicalTrials.gov trial NCT03660163.