高压调控的磁性量子临界点和非常规超导电性

发布时间：2018-03-20 10:43

本文选题：高压调控　切入点：磁性量子临界点　出处：《物理学报》2017年03期 　论文类型：期刊论文

【摘要】：通过化学掺杂或者施加高压等调控手段抑制长程磁有序可以实现磁性量子临界点,在其附近往往伴随出现诸如非费米液体行为或者非常规超导电性等奇特物理现象.相比于化学掺杂,高压调控具有不引入晶格无序和精细调控等优点.利用能提供良好静水压环境的立方六面砧和活塞-圆筒高压低温测量装置,首先系统研究了具有双螺旋磁有序结构的CrAs和MnP单晶的高压电输运行为,分别在P_c≈0.8 GPa和8 GPa实现了它们的磁性量子临界点,并在P_c附近分别观察到T_c=2 K和1 K的超导电性,相继实现了铬基和锰基化合物超导体零的突破;然后,详细测量了FeSe单晶高压下的电阻率和交流磁化率,绘制了详尽的温度-压力相图,揭示了电子向列序、长程反铁磁序和超导相之间的相互竞争关系,特别是在接近磁有序消失的临界点P_c≈6GPa附近观察到T_c~(max)=38.5K的高温超导电性,表明临界反铁磁涨落对FeSe中的高温超导电性起重要作用.
[Abstract]:Inhibition of long-range magnetic order can be achieved by applying high magnetic quantum critical point control by means of chemical doping or in its vicinity, often accompanied by problems such as non Fermi liquid behavior or unconventional superconductivity and other strange phenomena. Compared with chemical doping, pressure regulation has the advantages of no introduction of lattice disorder and fine regulation. The use of energy provide high static pressure environment six cubic anvil surface and piston cylinder of high pressure low temperature measuring device, first studied electric magnetic ordering with double spiral structure of CrAs and the transport behavior of MnP single crystal, the magnetic quantum critical point are realized in the P_c = 0.8 GPa and 8 GPa, and in the vicinity of P_c respectively. The observed T_c=2 K and 1 K superconductivity, have realized the chromium matrix and manganese oxide superconductor zero breakthrough; then, FeSe single crystal under high pressure resistivity and AC susceptibility measurement with Detailed, temperature pressure diagrams, reveals the electronic nematic order, long-range antiferromagnetic order and superconducting phase between the competition, especially in the vicinity of the critical point to observe the magnetic ordering is 6GPa to T_c~ the disappearance of the P_c (max) =38.5K high temperature superconductivity, that critical antiferromagnetic the fluctuations of the important role of high temperature superconductivity in FeSe.

【作者单位】：中国科学院物理研究所极端条件物理重点实验室;
【基金】：国家自然科学基金(批准号:11574377) 国家重点基础研究发展计划(批准号:2014CB921500) 中国科学院先导B项目(批准号:XDB07020100)资助的课题~~
【分类号】：O521.2

【相似文献】