Li Ming, Zhao Zheng-Yin, Sheng Jia-Yi
College of Science, Xuchang University, Xuchang, 461000, China.
Sci Rep. 2025 Jan 6;15(1):870. doi: 10.1038/s41598-024-81964-0.
Spin and valley polarizations (P and P) and tunneling magnetoresistance (TMR) are demonstrated in the ferromagnetic/barrier/normal/barrier/ferromagnetic WSe junction, with the gate voltage and off-resonant circularly polarized light (CPL) applied to the two barrier regions. The minimum incident energy of non-zero spin- and valley-resolved conductance has been derived, which is consistent with numerical calculations and depends on the electric potential U, CPL intensity ΔΩ, exchange field h, and magnetization configuration: parallel (P) or antiparallel (AP). For the P (AP) configuration, the energy region with P = -1 or P = 1 is wider (narrower) and increases with ΔΩ. As h increases, the P = 1 (P = -1 or P = 1) plateau becomes wider (narrower) for the P (AP) configuration. As U increases, the energy region with P = -1 increases first and then moves parallel to the E-axis, and the energy region with P = 1 for the P configuration remains unchanged first and then decreases. The energy region for TMR = 1 increases rapidly with h, remains unchanged first and then decreases as U increases, and has little dependence on ΔΩ. When the helicity of the CPL reverses, the valley polarization will switch. This work sheds light on the design of spin-valley and TMR devices based on ferromagnetic WSe double-barrier junctions.
在铁磁/势垒/正常/势垒/铁磁WSe结中展示了自旋和谷极化（P和P）以及隧穿磁电阻（TMR），其中栅极电压和非共振圆偏振光（CPL）施加于两个势垒区域。已推导出自旋和谷分辨电导非零的最小入射能量，这与数值计算一致，并且取决于电势U、CPL强度ΔΩ、交换场h和磁化配置：平行（P）或反平行（AP）。对于P（AP）配置，P = -1或P = 1的能量区域更宽（更窄），并且随ΔΩ增加。随着h增加，对于P（AP）配置，P = 1（P = -1或P = 1）的平台变宽（变窄）。随着U增加，P = -1的能量区域先增加然后平行于E轴移动，并且对于P配置，P = 1的能量区域先保持不变然后减小。TMR = 1的能量区域随h迅速增加，随着U增加先保持不变然后减小，并且对ΔΩ几乎没有依赖性。当CPL的螺旋度反转时，谷极化将切换。这项工作为基于铁磁WSe双势垒结的自旋谷和TMR器件的设计提供了启示。
