Native Approach to Controlled-Z Gates in Inductively Coupled Fluxonium Qubits.

The fluxonium qubits have emerged as a promising platform for gate-based quantum information processing. However, their extraordinary protection against charge fluctuations comes at a cost: when coupled capacitively, the qubit-qubit interactions are restricted to XX interactions. Consequently, effective ZZ or XZ interactions are only constructed either by temporarily populating higher-energy states, or by exploiting perturbative effects under microwave driving. Instead, we propose and demonstrate an inductive coupling scheme, which offers a wide selection of native qubit-qubit interactions for fluxonium. In particular, we leverage a built-in, flux-controlled ZZ interaction to perform qubit entanglement. To combat the increased flux-noise-induced dephasing away from the flux-insensitive position, we use a continuous version of the dynamical decoupling scheme to perform noise filtering. Combining these, we demonstrate a 20 ns controlled-z gate with a mean fidelity of 99.53%. More than confirming the efficacy of our gate scheme, this high-fidelity result also reveals a promising but rarely explored parameter space uniquely suitable for gate operations between fluxonium qubits.

The Association Between National Institutes of Health Stroke Scale Score and Clinical Outcome in Patients with Large Core Infarctions Undergoing Endovascular Treatment.

INTRODUCTION: This study aimed to analyze the association between baseline National Institutes of Health Stroke Scale (NIHSS) scores and clinical outcomes in patients with large core infarctions undergoing endovascular treatment (EVT), a relationship that remains unclear. METHODS: Data were obtained from the MAGIC study, a prospective multicenter cohort study focusing on patients with acute large core ischemic stroke. This analysis evaluated the impact of NIHSS scores on EVT outcomes in patients with large core infarctions. Primary outcome metrics included favorable outcomes (modified Rankin Scale [mRS] of 0-3 at 90 days), while secondary outcomes encompassed shifts in mRS scores, functional independence (mRS score of 0-2), mRS score of 0-4, and successful recanalization rates. Adverse events considered were symptomatic intracranial hemorrhage (sICH) and mortality. RESULTS: A total of 490 patients were enrolled in this study. Higher baseline NIHSS scores were inversely correlated with favorable outcomes (adjusted odds ratio [OR] in model 3, 0.848 [0.797-0.903], P < 0.001), particularly in patients with NIHSS scores above 20 (adjusted OR in model 3, 0.518 [0.306-0.878] vs. 0.290 [0.161-0.523]). Regarding adverse events, higher baseline NIHSS scores significantly correlated with increased 90-day mortality rates (adjusted OR in model 3, 1.129 [1.072-1.189], P < 0.001). This correlation became insignificant when baseline NIHSS scores exceeded 22. Additionally, baseline NIHSS scores partially mediated the association between age (indirect effect = - 0.0005, 19.39% mediated) and sex (indirect effect = 0.0457, 25.08% mediated) with the primary outcome. CONCLUSIONS: The findings indicate that higher baseline NIHSS scores correlate with poorer outcomes and increased mortality, particularly when scores exceed 20. Moreover, age and sex indirectly influence favorable outcomes through their association with baseline NIHSS scores.

High-Cycle, Push-Pull Fatigue Fracture Behavior of High-C, Si-Al-Rich Nanostructured Bainite Steel.

The high-cycle, push-pull fatigue fracture behavior of high-C, Si-Al-rich nanostructured bainitic steel was studied through the measurement of fatigue limits, a morphology examination and phase composition analysis of the fatigue fracture surface, as well as fractography of the fatigue crack propagation. The results demonstrated that the push-pull fatigue limits at 107 cycles were estimated as 710-889 MPa, for the samples isothermally transformed at the temperature range of 220-260 °C through data extrapolation, measured under the maximum cycle number of 105. Both the interior inclusion and the sample surface constituted the fatigue crack origins. During the fatigue crack propagation, a high amount of secondary cracks were formed in almost parallel arrangements. The apparent plastic deformation occurred in the fracture surface layer, which induced approximately all retained austenite to transform into martensite.

Effect of Austenitising Temperature on Mechanical Properties of Nanostructured Bainitic Steel.

Nanostructured bainite was obtained in high-carbon Si-Al-rich steel by low-temperature (220-260 °C) isothermal transformation after austenitisation at different temperatures (900 °C, 1000 °C, and 1150 °C). Improved strength-ductility-toughness balance was achieved in the nanostructured bainitic steel austenitised at low temperatures (900 °C and 1000 °C). Increasing the austenitising temperature not only coarsened prior austenite grains and bainite packets, but also increased the size and fraction of blocky retained austenite. High austenitising temperature (1150 °C) remarkably decreased ductility and impact toughness, but had a small effect on strength and hardness.