Monolayers (MLs) of transition-metal dichalcogenides (TMDs) exhibit unusual electrical behaviour under magnetic fields due to their intrinsic spin–orbit coupling and lack of inversion symmetry^{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}. Although recent experiments have also identified the critical role of carrier interactions within these materials^11,15, a complete mapping of the ambipolar Landau level (LL) sequence has remained elusive. Here we use single-electron transistors (SETs)^16,17 to perform LL spectroscopy in ML WSe₂, and provide a comprehensive picture of the electronic structure of a ML TMD for both electrons and holes. We find that the LLs differ notably between the two bands, and follow a unique sequence in the valence band (VB) that is dominated by strong Zeeman effects. The Zeeman splitting in the VB is several times higher than the cyclotron energy, far exceeding the predictions of a single-particle model and, moreover, tunes significantly with doping¹⁵. This implies exceptionally strong many-body interactions, and suggests that ML WSe₂ can serve as a host for new correlated-electron phenomena.

过渡金属二硫化氢（TMDs）的单层（MLs）由于其固有的自旋-轨道耦合和缺乏反演对称性^{1,2,3,4,5,6,7,8,9，}而在磁场下表现出异常的电行为^{。 10,11,12,13,14,15}。尽管最近的实验也已经确定了这些材料^11,15中载流子相互作用的关键作用，但双极性朗道能级（LL）序列的完整图谱仍然难以捉摸。在这里，我们使用单电子晶体管（SET）^16,17在ML WSe _2中执行LL光谱，并提供了针对电子和空穴的ML TMD的电子结构的综合图。我们发现，LLs在两个频带之间存在显着差异，并且在价带（VB）中遵循由强塞曼效应主导的唯一序列。VB中的塞曼分裂比回旋加速器能量高出几倍，远远超过了单粒子模型的预测，而且在掺杂^15时调谐明显。这意味着极强的多体相互作用，并暗示ML WSe ₂可以充当新的相关电子现象的宿主。