Orientation of point nodes and nonunitary triplet pairing tuned by the easy-axis magnetization in UTe2

The gap structure of a novel uranium-based superconductor UTe$_2$, situated in the vicinity of ferromagnetic quantum criticality, has been investigated via specific-heat $C(T,H,\Omega)$ measurements in various field orientations. Its angular $\Omega(\phi,\theta)$ variation shows a characteristic shoulder anomaly with a local minimum in $H \parallel a$ at moderate fields rotated within the $ab$ and $ac$ planes. Based on the theoretical calculations, these features can be attributed to the presence of point nodes in the superconducting gap along the $a$ direction. Under the field orientation along the easy-magnetization $a$ axis, an unusual temperature dependence of the upper critical field at low fields together with a convex downward curvature in $C(H)$ were observed. These anomalous behaviors can be explained on the basis of a nonunitary triplet state model with equal-spin pairing whose $T_{\rm c}$ is tuned by the magnetization along the $a$ axis. From these results, the gap symmetry of UTe$_2$ is most likely described by a vector order parameter of $d(k)=(b + ic)(k_b + ik_c)$.Comment: 6 pages, 4 figures (main text) + 7 pages, 5 figures (Supplementary Material), accepted for publication in Phys. Rev. Researc

プレホスピタル ノ ゲンバ ニオケル ガイショウ ショリョウ

From our experience of emergency cases, the careful prehospital care and treatment are critical factors in good recovery. Diagnosis of the blunt injury, triage, initial therapy and the decision of the adequate institusion are principal for paramedics. We participated in the trauma seminar for japanese paramedics. In the seminar, we learned the method of the primary care for traumatic patient modified from BTLS (Basic trauma life support), which is called PTCJ ( Prehospital Trauma Care Japan). Recently, we used the long-board to secure the neck and the back of the injured-patient. It is helpful for safe transportation because we can prevent the aggravation of spinal injury by keeping the patient’s neck straight. We applied the PTCJ in 3 cases, and the outcomes were satisfactory. We regard the PTCJ should be applied more widely

ビョウインマエ シンパイ テイシ ニオケル キュウキュウ キュウメイシ ノ キカン ソウカン ニツイテ : ホンケン ノ ゲンジョウ ト コンゴ ノ カダイ

Activities of Japanese Paramedics have increased and advanced year by year. Especially, intubation for OHCPA（out of hospital cardiopulmonary arrest） is approved since July 2004, but it is necessary to finish the training in Fire-fighter’s school and intubation practice in hospitals. In Fire-fighter’s school, Paramedics attend lectures and simulation, and in hospital, intubation practice for patients. Medical-control is the system for keeping the qualities and verification of details in the scene of pre-hospital medical care. This report discusses the states and problems of paramedic intubation, practice in hospital, airway management, from the questionnaire survey

Pressure-induced coherent sliding-layer transition in the excitonic insulator Ta2NiSe5

励起子絶縁体である積層構造物質Ta2NiSe5の高圧下における結晶構造を単結晶及び粉末シンクロトロンX線回折測定により決定した。常圧の単斜晶励起子絶縁体相IIは、加温または圧力下において半導体の斜方晶相Iへ転移する。より高い圧力（> 3GPa）では、斜方晶の半金属相IIIへの転移が起こる。この相Iから相IIIへの転移は、弱く結合した層が結晶全体でコヒーレントにスライドして起こる圧力誘起一次相転移であり、層間Seイオン間の幾何学的配置におけるクーロン相互作用によって大きく影響される。さらに低温では相IIIは単斜晶相IVに転移し、励起子絶縁体相IIに類似した構造となる。観測された層のスライドにもかかわらず、励起子相互作用が保持されているように見える

Pressure-induced coherent sliding-layer transition in the excitonic insulator Ta2NiSe5

The crystal structure of the excitonic insulator Ta2NiSe5 has been investigated under a range of pressures, as determined by the complementary analysis of both single-crystal and powder synchrotron X-ray diffraction measurements. The monoclinic ambient-pressure excitonic insulator phase II transforms upon warming or under a modest pressure to give the semiconducting C-centred orthorhombic phase I. At higher pressures (i.e. >3 GPa), transformation to the primitive orthorhombic semimetal phase III occurs. This transformation from phase I to phase III is a pressure-induced first-order phase transition, which takes place through coherent sliding between weakly coupled layers. This structural phase transition is significantly influenced by Coulombic interactions in the geometric arrangement between interlayer Se ions. Furthermore, upon cooling, phase III transforms into the monoclinic phase IV, which is analogous to the excitonic insulator phase II. Finally, the excitonic interactions appear to be retained despite the observed layer sliding transition

Maximizing T c by tuning nematicity and magnetism in FeSe1−x S x superconductors

鉄系超伝導体であるFeSeにおいて、元素置換による化学的加圧と物理的加圧を複合的に用いることで、新しい高温超伝導相を発見しました。多くの鉄系超伝導体とは異なりFeSeではこれらの2つの圧力効果に違いがあることが知られていました。化学的圧力ではこの物質が示す電子液晶相が抑制され、一方で物理圧力では磁性相が出現します。本研究では化学的加圧と物理的加圧の2つを網羅的に調べることにより、電子液晶相と磁性相の両方が消失した状態を作り出すことに成功し、その領域で新しい高温超伝導が出現することを発見しました