Superconductor -Insulator Transition in Cuprates

我们每年都会在这里介绍这项研究的精选成果。对于想了解这项工作细节的人，我们希望他们看看下面的文献。第一年：1)我们发现在压力下诱导的THT相的超导电性在x_c=0.05时不连续地消失。5)从隧道谱中我们发现x=0.02的低掺杂LSCO没有超导电性。3)我们成功地生长了高质量的电子掺杂NCCO单晶。第二年：1)对平面内输运性质的详细研究表明，二维金属导电对于高温超导来说是必不可少的。2)我们在Ca2RuO_4中发现了压力诱导的反铁磁Mott绝缘体-巡回铁磁金属相变。4.3)我们在横向弹性模的T依赖关系中发现了时间不可逆的二维Sc序参数。去年：1)超低幅度交流磁场磁化率测量澄清了Tc2以上位相非相干Cooper对的存在。2)我们发现了压力诱导的超导-绝缘体首次发现了CuRh_2S_4中的跃迁。3)首次发现了UCu2SN中铁四极有序的实验证据

We present here selected achievements in this study annually. To people who want to learn the details of this work, we hope them to look at the references below.The first year:1) We found that the superconductivity in THT phase induced under pressure disappears discontinuously at x_c=0.05.2) From the tunnel spectroscopy, we found that low doped LSCO with x=0.02 which has no superconductivity has an energy gap.3) We succeeded in growing high quality single-crystals of electron doped NCCO. Ultrasonics clarified the CEF state of Nd ions.The second year:1) Detailed research on in-plane transport properties revealed that the 2-D metallic conduction is indispensable for high-Tc SC.2) We found pressure induced antiferromagnetic Mott insulator -itinerant ferromagnetic metal transition in Ca_2RuO_4.3) We detected an evidence for time irreversible 2-D SC order parameter in the T-dependence of transverse elastic modulus.The last year:1) Ultra low amplitude AC field susceptibility measurements clarified the presence of phase incoherent Cooper pair above Tc.2) We found the pressure-induced superconductor-insulator transition in a spinet compound CuRh_2S_4 for the first time.3) We firstly detected the experimental evidence for the ferroquadrupolar ordering in UCu_2Sn