90 research outputs found
Enhancing the Superconducting Transition Temperature due to Strong-Coupling Effect under Antiferromagnetic Spin Fluctuations in CeRh1-xIrxIn5 : 115In-NQR Study
We report on systematic evolutions of antiferromagnetic (AFM) spin
fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF)
compounds CeRhIrIn via In
nuclear-quadrupole-resonance (NQR) experiment. The measurements of nuclear
spin-lattice relaxation rate have revealed the marked development of
AFM spin fluctuations as a consequence of approaching an AFM ordered state with
increasing Rh content. Concomitantly the superconducting transition temperature
and the energy gap increase drastically from K and in CeIrIn up to K and in
CeRhIrIn, respectively. The present work suggests that the
AFM spin fluctuations in close proximity to the AFM quantum critical point are
indeed responsible for the onset of strong-coupling unconventional SC with the
line node in the gap function in HF compounds.Comment: 4pages,5figures,to appear in Phys. Rev. Let
Search for the field-induced magnetic instability around the upper critical field of superconductivity in H || c in CeCoIn5
We present nuclear spin-lattice relaxation rate (1/T1) at the Co site and
ac-susceptibility results in the normal and superconducting (SC) states of
CeCoIn5 for H || c near the SC upper critical field Hc2 above 0.1 K. At 4.2 T,
1/T1 rapidly decreases below the SC transition temperature, consistent with the
previous reports. Although the field dependence of 1/T1T at 0.1 K shows a peak
at 5.2 T above Hc2, the temperature dependence of 1/T1T at 5.2 T is independent
of temperature below 0.2 K, showing a Fermi-liquid behavior. In addition, we
found no NMR-spectrum broadening by the appearance of internal fields around
Hc2 at 0.1 K. We could not detect any field-induced magnetic instability around
Hc2 down to 0.1 K although the remarkable non-Fermi-liquid behavior towards Hc2
was observed in various physical quantities.Comment: 6 pages, 3 figure
Duration of Postoperative Fever as a Simple and Useful Prognostic Indicator in Gastric Cancer Patients
[Background] Postoperative inflammation is associated with cancer progression in several cancers. However, the prognostic significance of postoperative fever remains unclear in gastric cancer patients. [Methods] We enrolled 442 patients with a histopathological diagnosis of gastric adenocarcinoma who underwent curative surgery. [Results] The mean duration of postoperative fever ≥ 37°C was 8.7 days (range: 0–186 days) and significantly longer in patients with advanced gastric cancer, venous invasion, and open or total gastrectomy vs. patients with early gastric cancer (P = 0.0072), no venous invasion (P = 0.025), laparoscopic gastrectomy (P = 0.027), and either proximal or distal partial gastrectomy (P = 0.0015). Five-year overall survival rates were 69.5% vs. 83.6% in the prolonged postoperative fever group (≥ 6 days of ≥ 37°C) vs. the nonprolonged group (< 6 days of ≥ 37°C), respectively (P = 0.0008). In patients without Clavien-Dindo classification postoperative infectious complications grade ≥ 2, 5-year overall survival was 69.7% vs. 84.0% in patients with prolonged postoperative fever vs. those without, respectively (P = 0.0067). Five-year disease-specific survival was 85.9% vs. 93.1% in patients with prolonged fever vs. those without, respectively (P = 0.041). Multivariate analysis indicated that postoperative fever was an independent prognostic indicator. [Conclusion] Postoperative fever ≥ 37°C duration may be useful in predicting prognosis in gastric cancer patients
Spin polarization gate device based on the chirality-induced spin selectivity and robust nonlocal spin polarization
Nonlocal spin polarization phenomena are thoroughly investigated in the
devices made of chiral metallic single crystals of CrNbS and NbSi
as well as of polycrystalline NbSi. We demonstrate that simultaneous
injection of charge currents in the opposite ends of the device with the
nonlocal setup induces the switching behavior of spin polarization in a
controllable manner. Such a nonlocal spin polarization appears regardless of
the difference in the materials and device dimensions, implying that the
current injection in the nonlocal configuration splits spin-dependent chemical
potentials throughout the chiral crystal even though the current is injected
into only a part of the crystal. We show that the proposed model of the spin
dependent chemical potentials explains the experimental data successfully. The
nonlocal double-injection device may offer significant potential to control the
spin polarization to large areas because of the nature of long-range nonlocal
spin polarization in chiral materials.Comment: 8 pages, 8 figure
Chirality-selected crystal growth and spin polarization over centimeters of transition metal disilicide crystals
We performed a chirality-controlled crystal growth of transition metal
disilicide NbSi and TaSi by using a laser-diode-heated floating
zone (LDFZ) method. The crystal chirality was evaluated in the crystals of
centimeters in length by performing single crystal X-ray diffraction as well as
probing a spin polarization originating from chirality-induced spin selectivity
(CISS) effect. The crystals of right-handed NbSi and of left-handed
TaSi were obtained in the conventional LDFZ crystal growth, while the
left-handed NbSi and right-handed TaSi crystals were grown by the
LDFZ method with the composition-gradient feed rods. The spin polarization via
the CISS was observed over centimeters in the NbSi single crystals and
the sign of the CISS signals was dependent on the chirality of crystals. The
correlation between the crystal chirality and CISS signals indicates that the
CISS measurements work as a non-destructive method for chirality determination
even in centimeter-long specimens.Comment: 9 pages, 6 figure
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