压力驱动下双梯形结构$A$ Fe $_2$ PDMATHAAC $_3$（$A$ =Ba或K，$X$ =S或Se）从反铁磁半导体到金属的相变
Pressure-driven phase transition from antiferromagnetic semiconductor to nonmagnetic metal in two-leg ladders $A$Fe$_2$$X$$_3$ ($A$=Ba or K, $X$=S or Se)
摘要：
BaFe $_2$ S $_3$ [Takahashi { \it et al.}，Nat.板牙. { \bf 14}，1008（2015）]已经激发了对123型铁硫属化物的相当大的兴趣。这种材料是第一个报道的铁基双腿梯形超导体，而不是铁超导体家族的主流二维层状结构。一旦流体静压超过$11$ GPa，BaFe $_2$ S $_3$在低于$24$ ~K时从半导体变为超导体。虽然以前的计算正确地解释了它的基态磁态和电子结构，压力诱导的相变没有成功地再现。在这项工作中，我们的第一性原理计算发现，随着压力的增加，晶格常数以及局部磁矩逐渐被抑制，随后在临界压力下发生一阶磁转变，局部磁矩突然下降到零。我们的计算表明，由电子从S转移到Fe引起的自掺杂可能在这种转变中起着关键作用。在高压下形成一种非金属相可能为超导性铺平道路。作为这一努力的延伸，还研究了另外两种123型铁硫族化物KFe $_2$ S $_3$和KFe $_2$ Se $_3$。KFe $_2$ S $_3$随压力增加也显示一级相变，但KFe $_2$ Se $_3$显示二级或弱一级相变。用于KFe $_2$ S $_3$和KFe $_2$ Se $_3$的淬灭磁性所需的压力高于BaFe $_2$ S $_3$。进一步的实验可以证实BaFe $_2$ S $_3$和KFe $_2$ S $_3$中预测的一级跃迁性质，以及其他123型铁硫属化物在高压下可能的金属/超导状态。
英文摘要：
The recent discovery of superconductivity in BaFe$_2$S$_3$ [Takahashi {\it et al.}, Nat. Mater. {\bf 14}, 1008 (2015)] has stimulated considerable interest in 123-type iron chalcogenides. This material is the first reported iron-based two-leg ladder superconductor, as opposed to the prevailing two-dimensional layered structures of the iron superconductors family. Once the hydrostatic pressure exceeds $11$ GPa, BaFe$_2$S$_3$ changes from a semiconductor to a superconductor below $24$~K. Although previous calculations correctly explained its ground state magnetic state and electronic structure, the pressure induced phase transition was not successfully reproduced. In this work, our first principles calculations find that with increasing pressure the lattice constants as well as local magnetic moments are gradually suppressed, followed by a first-order magnetic transition at a critical pressure, with local magnetic moments dropping to zero suddenly. Our calculations suggests that the self-doping caused by electrons transferred from S to Fe may play a key role in this transition. The development of a nonmagnetic metallic phase at high pressure may pave the way to superconductivity. As extensions of this effort, two other 123-type iron chalcogenides, KFe$_2$S$_3$ and KFe$_2$Se$_3$, have also been investigated. KFe$_2$S$_3$ also displays a first-order transition with increasing pressure, but KFe$_2$Se$_3$ shows instead a second-order, or weakly first-order, transition. The required pressures for KFe$_2$S$_3$ and KFe$_2$Se$_3$ to quench the magnetism are higher than for BaFe$_2$S$_3$. Further experiments can confirm the predicted first-order nature of the transition in BaFe$_2$S$_3$ and KFe$_2$S$_3$, as well as the possible metallic/superconductivity state in other 123-type iron chalcogenides under high pressure.
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。
