arXiv subjects

Tomohito Nakano

Publications and source records attributed to Tomohito Nakano.

2 recordsLinked to original sources

arXiv2018

Superconducting gap symmetry of the BiS$_2$-based superconductor LaO$_{0.5}$F$_{0.5}$BiSSe elucidated through specific heat measurement

In this study, the superconducting gap symmetry of LaO$_{0.5}$F$_{0.5}$BiSSe is elucidated through specific heat measurements with one single crystal of LaO$_{0.5}$F$_{0.5}$BiSSe. A clear jump is observed at 3.95 K in LaO$_{0.5}$F$_{0.5}$BiSSe, suggesting bulk superconductivity. From specific heat measurements, $ΔC_\mathrm{e}/γT_\mathrm{c}$ and 2$Δ$(0)/$k_\mathrm{B}T_\mathrm{c}$ are obtained as 2.31 and 4.5. These values indicate strong electron-phonon coupling superconductivity. The temperature ($T$) and magnetic-field ($H$) dependence of the electronic specific heat $C_\mathrm{e}(T, H)$ suggests that superconductivity is fully gapped. Our handmade system successfully elucidates superconducting gap symmetry of the BiS$_2$-based compound with a small single crystal.

cond-mat.supr-con↗

arXiv2005

Giant nonlinear conduction and thyristor-like negative derivative resistance in BaIrO3 single crystals

We synthesized single-crystalline samples of monoclinic BaIrO3 using a molten flux method, and measured their magnetization, resistivity, Seebeck coefficient and nonlinear voltage-current characteristics. The magnetization rapidly increases below a ferromagnetic transition temperature TC of 180 K, where the resistivity concomitantly shows a hump-type anomaly, followed by a sharp increase below 30 K. The Seebeck coefficient suddenly increases below TC, and shows linear temperature dependence below 50 K. A most striking feature of this compound is that the anomalously giant nonlinear conduction is observed below 30 K, where a small current density of 20 A/cm2 dramatically suppresses the sharp increase in resistivity to induce a metallic conduction down to 4 K.

cond-mat.str-el↗