论文标题
fe $ _ {1+y}的电子相图
Electronic phase diagram of Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ revealed by magnetotransport measurements
论文作者
论文摘要
在基于Fe的超导体中，Fe $ _ {1+y} $ te $ _ {1-x} $ se $ _ {x} $是独一无二的，因为它的晶体结构是最简单的，并且电子相关级别是最强的，因此对于调查掺杂（$ x $） - 温度（$ t $）的相位很重要。但是，目前不可避免地将多余的FE纳入了超过的FE，可以阻止建立真实的相图。我们通过开发一种新的退火方法来克服上述重大问题，称为“解放”，其中单晶在Te蒸气下被退火。具体来说，我们对TE灭绝的超导fe $ _ {1+y} $ te $ _ {1-x} $ se $ _ {x} $进行了各种磁转运测量。我们观察到，从不连贯的到相干电子状态和伪造的开放发生在高温下（$ \ $ \ $ \ $ \ $ x $ = 0.2）。在较低温度下具有多带性质的阶段的出现（$ \ $ \ $ 50 k，对于$ x $ = 0.2 $ = 0.2）。
Among the Fe-based superconductors, Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ is unique in that its crystal structure is the simplest and the electron correlation level is the strongest, and thus it is important to investigate the doping($x$)-temperature ($T$) phase diagram of this system. However, inevitably incorporated excess Fe currently prevents the establishment of the true phase diagram. We overcome the aforementioned significant problem via developing a new annealing method termed as "Te-annealing" wherein single crystals are annealed under Te vapor. Specifically, we conducted various magnetotransport measurements on Te-annealed superconducting Fe$_{1+y}$Te$_{1-x}$Se$_{x}$. We observed that crossover from the incoherent to the coherent electronic state and opening of the pseudogap occurs at high temperatures ($\approx$ 150 K for $x$ = 0.2). This is accompanied by a more substantial pseudogap and the emergence of a phase with a multi-band nature at lower temperatures (below $\approx$ 50 K for $x$ = 0.2) before superconductivity sets in. Based on the results, the third type electronic phase diagram in Fe-based high-$T_c$ superconductors is revealed.
