论文标题
对比的是在黄铁矿FES $ _2 $的相反的铁磁性，化学掺杂与静电门控
Contrasting Ferromagnetism in Pyrite FeS$_2$ Induced by Chemical Doping versus Electrostatic Gating
论文作者
论文摘要
静电门控的最新进展提供了一种新颖的方法，可以通过静电量而不是化学掺杂来改变材料中的载体浓度，从而最大程度地减少了杂质散射。在这里，我们使用第一原理密度功能理论，结合了紧密结合方法来比较和对比静电门控和CO化学掺杂对FES $ _2 $的铁磁过渡的影响，这是一种过渡金属二硫化物与黄铁矿结构。使用从最大位置的Wannier函数获得的紧密结合参数，我们计算了宽阔的掺杂范围内的磁敏感性。我们发现，静电门控所需的电子浓度要比同等掺杂的等效物具有更高的电子浓度，才能通过石膏样机制诱导铁磁性。我们将这种行为归因于在化学掺杂下在传导带底部附近的狭窄CO带的形成，在静电门控案例中不存在。我们的结果表明，静电门控的影响超出了简单的刚性带移位，并强调了通过门控促进的晶体结构变化的重要性。
Recent advances in electrostatic gating provide a novel way to modify the carrier concentration in materials via electrostatic means instead of chemical doping, thus minimizing the impurity scattering. Here, we use first-principles Density Functional Theory combined with a tight-binding approach to compare and contrast the effects of electrostatic gating and Co chemical doping on the ferromagnetic transition of FeS$_2$, a transition metal disulfide with the pyrite structure. Using tight-binding parameters obtained from maximally-localized Wannier functions, we calculate the magnetic susceptibility across a wide doping range. We find that electrostatic gating requires a higher electron concentration than the equivalent in Co doping to induce ferromagnetism via a Stoner-like mechanism. We attribute this behavior to the formation of a narrow Co band near the bottom of the conduction band under chemical doping, which is absent in the electrostatic gating case. Our results reveal that the effects of electrostatic gating go beyond a simple rigid band shift, and highlight the importance of the changes in the crystal structure promoted by gating.
