We propose a valley filter based on 8-Pmmn borophene which hosts two tilted Dirac cones. It is found that the application of a magnetic-electric barrier provided by a single ferromagnetic gate is sufficient to create valley-polarized current in 8-Pmmn borophene. The valley polarization of output current depends on the barrier orientation. Due to an intrinsic symmetry, it vanishes when the barrier orientation is along the tilted direction of Dirac cones. For the barrier orientation perpendicular to the tilted direction, the valley polarization for a realistic magnetic barrier can approach nearly $100\%$ at proper Fermi energy and gate voltage. The remarkable valley contrast of conductance in this case is attributed to a new transmission resonance. The tilting of Dirac cones is essential for the predicted valley filtering. Our findings are helpful for valleytronic applications of two-dimensional materials with tilted Dirac cones.

中文翻译：

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基于 8-Pmmn 硼烯的各向异性和栅极可调谷值滤波

我们提出了一种基于 8-Pmmn 硼烯的谷滤波器，它承载两个倾斜的狄拉克锥。发现由单个铁磁栅极提供的磁电势垒的应用足以在 8-Pmmn 硼烯中产生谷极化电流。输出电流的谷极化取决于势垒方向。由于固有的对称性，当势垒方向沿着狄拉克锥的倾斜方向时，它就消失了。对于垂直于倾斜方向的势垒方向，在适当的费米能量和栅极电压下，实际磁势垒的谷极化可以接近 $100\%$。在这种情况下，电导的显着谷值对比归因于新的传输共振。狄拉克锥的倾斜对于预测的谷滤波是必不可少的。