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arXiv 2501.13635cond-mat.str-el
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二维极性金属相在范德瓦尔斯化合物FePSe₃中出现

Emergent Polar Metal Phase in a Van der Waals Mott Magnet

University of Cambridge(剑桥大学);Institut Laue-Langevin(朗之万研究所);University of Birmingham(伯明翰大学);University of East Anglia(东英吉利大学);Navoi State University of Mining and Technologies(纳沃伊国立矿业与技术大学);Diamond Light Source(钻石光源)
Shiyu Deng, Matthew J. Coak, Charles R. S. Haines, Hayrullo Hamidov, Giulio I. Lampronti, David M. Jarvis, Xiaotian Zhang, Cheng Liu, Dominik Daisenberger, Mark… 展开作者

Shiyu Deng, Matthew J. Coak, Charles R. S. Haines, Hayrullo Hamidov, Giulio I. Lampronti, David M. Jarvis, Xiaotian Zhang, Cheng Liu, Dominik Daisenberger, Mark R. Warren, Thomas C Hansen, Stefan Klotz, Chaebin Kim, Pengtao Yang, Bosen Wang, Jinguang Cheng, Je-Geun Park, Andrew R. Wildes, Siddharth S Saxena

AI总结:

FePSe₃在压力作用下出现可调的二维极性金属相,通过失去反演对称性实现,为研究该新型相提供了新平台。

摘要:

我们报告了在范德瓦尔斯化合物FePSe₃中,在中等压力下出现二维(2D)极性金属相。这种层状材料在常压条件下是莫特绝缘体,具有反铁磁序。我们展示FePSe₃独特地允许调节二维相关绝缘体进入一种奇特的金属状态,其中失去的反演对称性导致离子的周期性极性位移,在导电相中形成极性金属。我们的同步辐射和中子衍射数据使我们能够提出一个长期寻求的、无歧义的高压结构模型,并展示了该新相的极性位移。我们还观察到在绝缘体到金属转变时磁序的抑制,这与该结构变化相对应。我们的工作概述了FePSe₃的综合温度-压力相图,结合了详细的结构、磁性和输运数据。高压相在高温下表现出激活半导体行为,其电阻率在较低温度下表现出T²依赖性——尽管在这种情况下所需的“好金属”费米液体描述条件未被满足——以及低温电阻率的上升,当系统远离共存转变时会受到抑制。由于失去反演对称性与压力诱导的金属性相结合,FePSe₃中实现可调的二维极性金属态,为在可访问压力下研究这种奇特相提供了有前景的新平台。

英文摘要:

We report the emergence of a two-dimensional (2D) polar metal phase in van der Waals compound FePSe$_3$ under moderate pressures. This layered material is a Mott insulator with antiferromagnetic order under ambient conditions. We show that FePSe$_3$ uniquely allows tuning a 2D correlated insulator into an exotic metal state where a loss of inversion symmetry leads to periodic polar displacements of ions, within a conducting phase - a polar metal. Our combined synchrotron and neutron diffraction data allow us to present a long-sought, unambiguous high-pressure structural model and show the polar displacements of this new phase. We also observe the suppression of magnetic ordering at the insulator-to-metal transition correspondent with this structural change. Our work outlines a comprehensive temperature-pressure phase diagram of FePSe$_3$, combining detailed structural, magnetic and transport data. The high-pressure phase exhibits activated semiconductor behavior at high temperatures, a $T^2$-dependence in its resistivity at lower temperatures - despite the conditions required for a `good metal' Fermi-Liquid description not being met in this case - and a low-temperature resistivity upturn which is suppressed as the system is tuned away from the concomitant transitions. The realisation of a tunable 2D polar metal state in FePSe$_3$ due to the loss of its inversion symmetry combined with pressure-induced metallicity offers a promising new platform to investigate this exotic phase at accessible pressures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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