电子掺杂下FeSe二维性的增强

Enhancement of two dimensionality in electron-doped FeSe

本文利用离子液体调控对FeSe薄膜进行电子掺杂,研究了超导增强过程中FeSe超导涨落行为的演化.顺电导分析表明,随着温度降低,超导涨落维度从二维过渡到三维;并且,随着电子掺杂,三维涨落的温度区间逐渐减小,这表明FeSe层间耦合强度逐渐减弱,体系二维性增强.FeSe调控后的高T_(c)态与插层FeSe基材料不仅具有相近的T_(c)(~40 K),并且都表现出较强的二维性,这暗示着二维性的增强对于FeSe超导的增强起着重要作用.

In this work,the evolution of superconducting fluctuations in FeSe films with electron doping induced by the ionic liquid gating technique was reported.Paraconductivity analyses reveal that superconducting fluctuations change from two-to three-dimensional with decreasing temperature.Moreover,with electron doping,the temperature range of threedimensional fluctuations decreases gradually,indicating that the interlayer coupling of FeSe is gradually weakened,and its two dimensionality is improved.The high-T_(c) state of FeSe after gating shows similar T_(c)(~40 K)to that of intercalated FeSe-based materials;in addition,both of them exhibit strong two-dimensional characteristics.This suggests that the enhancement in two dimensionality plays a crucial role in improving the superconductivity in FeSe.