Xu Shuigang, Shen Junying, Long Gen, Wu Zefei, Bao Zhi-Qiang, Liu Cheng-Cheng, Xiao Xiao, Han Tianyi, Lin Jiangxiazi, Wu Yingying, Lu Huanhuan, Hou Jianqiang, An Liheng, Wang Yuanwei, Cai Yuan, Ho K M, He Yuheng, Lortz Rolf, Zhang Fan, Wang Ning
Department of Physics and Center for Quantum Materials, the Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA.
Phys Rev Lett. 2017 Feb 10;118(6):067702. doi: 10.1103/PhysRevLett.118.067702.
We fabricate high-mobility p-type few-layer WSe_{2} field-effect transistors and surprisingly observe a series of quantum Hall (QH) states following an unconventional sequence predominated by odd-integer states under a moderate strength magnetic field. By tilting the magnetic field, we discover Landau level crossing effects at ultralow coincident angles, revealing that the Zeeman energy is about 3 times as large as the cyclotron energy near the valence band top at the Γ valley. This result implies the significant roles played by the exchange interactions in p-type few-layer WSe_{2}, in which itinerant or QH ferromagnetism likely occurs. Evidently, the Γ valley of few-layer WSe_{2} offers a unique platform with unusually heavy hole carriers and a substantially enhanced g factor for exploring strongly correlated phenomena.
我们制备了高迁移率的p型少层WSe₂场效应晶体管，并令人惊讶地观察到，在中等强度磁场下，一系列量子霍尔（QH）态遵循以奇数整数态为主的非常规序列。通过倾斜磁场，我们在超低重合角处发现了朗道能级交叉效应，这表明在Γ谷价带顶附近，塞曼能量约为回旋能量的3倍。这一结果意味着交换相互作用在p型少层WSe₂中发挥了重要作用，其中可能会出现巡游或QH铁磁性。显然，少层WSe₂的Γ谷提供了一个独特的平台，具有异常重的空穴载流子和大幅增强的g因子，用于探索强关联现象。
