Wu Fan, Gibertini Marco, Watanabe Kenji, Taniguchi Takashi, Gutiérrez-Lezama Ignacio, Ubrig Nicolas, Morpurgo Alberto F
Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland.
Department of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland.
Nano Lett. 2023 Sep 13;23(17):8140-8145. doi: 10.1021/acs.nanolett.3c02274. Epub 2023 Aug 23.
Transistors realized on the 2D antiferromagnetic semiconductor CrPS exhibit large magnetoconductance due to magnetic-field-induced changes in the magnetic state. The microscopic mechanism coupling the conductance and magnetic state is not understood. We identify it by analyzing the evolution of the parameters determining the transistor behavior─carrier mobility and threshold voltage─with temperature and magnetic field. For temperatures near the temperature , the magnetoconductance originates from a mobility increase due to the applied magnetic field that reduces spin fluctuation induced disorder. For ≪ , instead, what changes is the threshold voltage, so that increasing the field at fixed gate voltage increases the density of accumulated electrons. The phenomenon is explained by a conduction band-edge shift correctly predicted by the calculations. Our results demonstrate that the band structure of CrPS depends on its magnetic state and reveal a mechanism for magnetoconductance that had not been identified earlier.
在二维反铁磁半导体CrPS上实现的晶体管，由于磁场引起的磁态变化而表现出大磁电导。目前尚不清楚耦合电导和磁态的微观机制。我们通过分析决定晶体管行为的参数（载流子迁移率和阈值电压）随温度和磁场的变化来确定它。对于接近某一温度的温度范围，磁电导源于施加磁场导致的迁移率增加，该磁场减少了自旋涨落诱导的无序。相反，当远低于该温度时，发生变化的是阈值电压，因此在固定栅极电压下增加磁场会增加积累电子的密度。该现象由计算正确预测的导带边缘移动来解释。我们的结果表明CrPS的能带结构取决于其磁态，并揭示了一种此前未被识别的磁电导机制。
