Manipulating a quantum state via electrostatic gating has been of great importance for many model systems in nanoelectronics. Until now, however, controlling the electron spins or, more specifically, the magnetism of a system by electric-field tuning has proven challenging^1,2,3,4. Recently, atomically thin magnetic semiconductors have attracted significant attention due to their emerging new physical phenomena^{5,6,7,8,9,10,11,12,13}. However, many issues are yet to be resolved to convincingly demonstrate gate-controllable magnetism in these two-dimensional materials. Here, we show that, via electrostatic gating, a strong field effect can be observed in devices based on few-layered ferromagnetic semiconducting Cr₂Ge₂Te₆. At different gate doping, micro-area Kerr measurements in the studied devices demonstrate bipolar tunable magnetization loops below the Curie temperature, which is tentatively attributed to the moment rebalance in the spin-polarized band structure. Our findings of electric-field-controlled magnetism in van der Waals magnets show possibilities for potential applications in new-generation magnetic memory storage, sensors and spintronics.

对于纳米电子学中的许多模型系统而言，通过静电门控操作量子态非常重要。然而，到目前为止，通过电场调谐来控制电子自旋，或更具体地说，控制系统的磁性已被证明具有挑战性^1,2,3,4。近来，由于原子薄的磁性半导体出现了新的物理现象^{5,6,7,8,9,10,11,12,13}而引起了人们的极大关注。但是，要说服论证这些二维材料中的栅极可控磁性，还有许多问题有待解决。在这里，我们表明，通过静电门控，可以在基于几层铁磁半导体Cr ₂ Ge ₂ Te _6的器件中观察到强场效应。在不同的栅极掺杂下，所研究器件中的微区Kerr测量结果表明，居里温度以下的双极可调谐磁化回路，暂时归因于自旋极化带结构中的力矩平衡。我们对范德华磁体中的磁场控制磁场的发现表明，在新一代磁存储器，传感器和自旋电子学中有潜在的应用潜力。