Variation of the superconducting order parameters in quasi-one-dimensional superconductors revealed by field-angle-resolved calorimetory under pressure

这个研究项目的目的是从热力学测量和压力实验中提取超导体的有趣特性。特别是，我们利用自己开发的灵敏量热计，尝试发现以往研究中无法解决的现象。本项目最重要的成果是自旋三重态超导体Sr 2 RuO 4的磁热效应测量结果。我们发现，在低温下，当磁场正好平行于晶体ab平面时，超导态-正常态的转变是一级的。这一事实表明，这种材料的超导电性被未知的机制破坏。此外，我们还通过比热测量揭示了有机超导体（TMTSF）_2ClO_4的超导能隙结构。我们还研究了单轴应变对钌氧化物的影响。

The purpose of this research project is to extract interesting properties of superconductors from thermodynamic measurements and from pressure experiments. In particular, by using sensitive calorimeters that we ourselves developed, we tried to discover phenomena that could not be resolved in previous studies.The most important achievement of this project is the result of the magnetocaloric effect measurements of the spin-triplet superconductor Sr2RuO4. We found that at low temperatures the superconducting-normal state transition is of first order when the magnetic field is exactly parallel to the crystalline ab plane. This fact indicates that the superconductivity in this material is destroyed by unknown mechanism. In addition, we revealed the superconducting gap structure of the organic superconductor (TMTSF)2ClO4 from specific heat measurements. We furthermore investigated uniaxial strain effects on ruthenium oxides.