Pressure-induced superconductivity in the quasi-one-dimensional charge density wave material CuTe
Pressure-induced superconductivity in the quasi-one-dimensional charge density wave material CuTe
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准一维电荷密度波材料 CuTe 中的压力诱导超导
DOI：
10.1103/physrevb.103.134518
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发表时间：
2021
影响因子：
3.7
通讯作者：
Yang Zhaorong
中科院分区：
文献类型：
--
作者：
Wang Shuyang;Chen Xuliang;An Chao;Zhou Ying;Zhou Yonghui;Gu Chuanchuan;Zhang Lili;Yang Xiaoping;Yang Zhaorong
CuTe具有层状正交结构(PmMn，第59号空间群)，但表现出准一维电荷密度波(CDW)有序。在这里，我们通过电输运、同步辐射X射线衍射、拉曼光谱测量和理论计算相结合的方法，在高达41.8-49.8 Gpa的压力下，对金刚石顶压室中的CUT进行了高压研究。输运实验表明，CDW的转变表现为电阻率的驼峰，随着外加压力的作用，其转变温度逐渐降低，电阻率驼峰的幅度迅速衰减。通过对${T}_{\mathm{cdw}}$与$P$趋势进行线性外推估计，CDW将完全抑制在10 Gpa以上。在进一步压缩时，在2.4K和20 GPa时，首先观察到电阻率的突然下降，然后在37 Gpa以上建立零电阻，这表明存在超导电性(SC)。结合X射线衍射谱和拉曼光谱数据，结合理论计算，证明在20 GPaSc的出现伴随着正交单斜晶系(8号空间群)的结构转变。
Copper monotelluride CuTe has a layered orthorhombic structure (space group Pmmn, No. 59) but exhibits a quasi-one-dimensional charge density wave (CDW) order. Here, we present a high-pressure study of CuTe in a diamond anvil cell at pressures up to 41.8--49.8 GPa, through a combination of electrical transport, synchrotron x-ray diffraction (XRD), and Raman spectroscopy measurements as well as theoretical calculations. Our transport experiments show that the CDW transition is manifested as a hump in resistivity; with the application of external pressure, its transition temperature ${T}_{\mathrm{CDW}}$ decreases gradually and the amplitude of the resistivity hump decays rapidly. The CDW gets suppressed completely above \ensuremath{\sim}10 GPa as estimated by a linear extrapolation of the ${T}_{\mathrm{CDW}}$ versus $P$ trend. Upon further compression, a sudden drop in resistivity is initially observed at \ensuremath{\sim}2.4 K and \ensuremath{\sim}20 GPa, and zero resistance is established above \ensuremath{\sim}37 GPa, suggesting the occurrence of superconductivity (SC). Combined XRD and Raman data as well as theoretical calculations together evidence that the emergence of SC at \ensuremath{\sim}20 GPa is accompanied by an orthorhombic to monoclinic (space group $\mathit{Cm}$, No. 8) structural transition.