压缩元素硫中的超导无公度主客体相
Superconducting incommensurate host-guest phases in compressed elemental sulfur
摘要：
我们使用密度泛函理论（DFT）和结构搜索方法表明，元素硫的基态是$386$ - $679$ GPa之间的钡-Ⅳ a型无公度主客体（HG）相，成为第一个被预测具有这种结构的VI族元素.在HG相内，硫经历一系列转变，其中相邻的客体链不对齐而是偏移不同的量，这可以被描述为链的堆叠顺序的重排。我们发现，这些链重排密切耦合到调制的主机和客户的原子，证明至关重要的稳定HG结构。与其他元素的高压HG相不同，硫不表现出间隙电荷局部化，而是具有强烈的局部化“空隙”，这些空隙耗尽了电子电荷。在采用HG结构之前，我们预测硫具有$Fdd2$对称性的正交结构。我们计算了这些新发现的相的超导临界温度，并表明$T_c$预计在$271$ GPa下在$24.8$和$28.2$ K之间达到峰值。
英文摘要：
We use Density Functional Theory (DFT) and structure searching methods to show that the ground state of elemental sulfur is a Barium-IVa type incommensurate host-guest (HG) phase between $386$-$679$ GPa, becoming the first group-VI element predicted to possess such a structure. Within the HG phase, sulfur undergoes a series of transitions in which adjacent guest chains are not aligned but rather offset by different amounts, which can be described as a rearrangement of the stacking order of the chains. We show that these chain rearrangements are intimately coupled to modulations of the host and guest atoms which prove crucial to stabilising the HG structure. Unlike the high-pressure HG phases of other elements, sulfur does not exhibit interstitial charge localisation, and instead features strongly localised `voids' that are depleted of electronic charge. Prior to adopting the HG structure, we predict that sulfur possesses an orthorhombic structure of $Fdd2$ symmetry. We calculate the superconducting critical temperatures of these newly discovered phases, and show that $T_c$ is expected to peak between $24.8$ and $28.2$ K at $271$ GPa.
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。
