103 research outputs found
Observation of domain wall bimerons in chiral magnets
Topological defects embedded in or combined with domain walls have been
proposed in various systems, some of which are referred to as domain wall
skyrmions or domain wall bimerons. However, the experimental observation of
such topological defects remains an ongoing challenge. Here, using Lorentz
transmission electron microscopy, we report the experimental discovery of
domain wall bimerons in chiral magnet Co-Zn-Mn(110) thin films. By applying a
magnetic field, multidomain structures develop, and simultaneously, chained and
isolated bimerons arise as the localized state between the domains with the
opposite in-plane components of net magnetization. The multidomain formation is
attributed to magnetic anisotropy and dipolar interaction, and domain wall
bimerons are stabilized by the Dzyaloshinskii-Moriya interaction. In addition,
micromagnetic simulations show that domain wall bimerons appear for a wide
range of conditions in chiral magnets with cubic magnetic anisotropy. Our
results promote further study in various fields of physics.Comment: 30 pages, 10 figures (including Supplementary Materials
Astrodynamics Science About Itokawa, Gravity and Ephemeris
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76347/1/AIAA-2006-6658-569.pd
Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: angle-resolved photoemission study
We performed angle-resolved photoemission spectroscopy with micro-focused
beam on a topological line-nodal compound CaSb2 which undergoes a
superconducting transition at the onset Tc~1.8 K, to clarify the Fermi-surface
topology relevant to the occurrence of superconductivity. We found that a
three-dimensional hole pocket at the G point is commonly seen for two types of
single-crystalline samples fabricated by different growth conditions. On the
other hand, the carrier-doping level estimated from the position of the
chemical potential was found to be sensitive to the sample fabrication
condition. The cylindrical electron pocket at the Y(C) point predicted by the
calculations is absent in one of the two samples, despite the fact that both
samples commonly show superconductivity with similar Ts's. This suggests a key
role of the three-dimensional hole pocket to the occurrence of
superconductivity, and further points to an intriguing possibility to control
the topological nature of superconductivity by carrier tuning in CaSb2.Comment: 7 pages, 3 figure
Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease
BACKGROUND: Intravascular ultrasound (IVUS) was only rarely used in landmark trials comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) in patients with multivessel disease. OBJECTIVES: The authors aimed to evaluate clinical outcomes after optimal IVUS-guided PCI in patients undergoing multivessel PCI. METHODS: The OPTIVUS (OPTimal IntraVascular UltraSound)-Complex PCI study multivessel cohort was a prospective multicenter single-arm study enrolling 1, 021 patients undergoing multivessel PCI, including left anterior descending coronary artery using IVUS, aiming to meet the prespecified criteria (OPTIVUS criteria: minimum stent area > distal reference lumen area [stent length ≥28mm], and minimum stent area >0.8 × average reference lumen area [stent length <28mm]) for optimal stent expansion. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) (death/myocardial infarction/stroke/any coronary revascularization). The predefined performance goals were derived from the CREDO-Kyoto (Coronary REvascularization Demonstrating Outcome study in Kyoto) PCI/CABG registry cohort-2 fulfilling the inclusion criteria in this study. RESULTS: In this study, 40.1% of the patients met OPTIVUS criteria in all stented lesions. The cumulative 1-year incidence of the primary endpoint was 10.3% (95% CI: 8.4%-12.2%), which was significantly lower than the predefined PCI performance goal of 27.5% (P < 0.001), and which was numerically lower than the predefined CABG performance goal of 13.8%. The cumulative 1-year incidence of the primary endpoint was not significantly different regardless of meeting or not meeting OPTIVUS criteria. CONCLUSIONS: Contemporary PCI practice conducted in the OPTIVUS-Complex PCI study multivessel cohort was associated with a significantly lower MACCE rate than the predefined PCI performance goal, and with a numerically lower MACCE rate than the predefined CABG performance goal at 1 year
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