Anomalously robust valley polarization and valley coherence in bilayer WS2

作者：Zhu, Bairen; Zeng, Hualing^*; Dai, Junfeng; Gong, Zhirui; Cui, Xiaodong

来源：Proceedings of the National Academy of Sciences, 2014, 111(32): 11606-11611.

DOI：10.1073/pnas.1406960111

• valleytronics
• spin-valley coupling
• valley quantum control

We report the observation of anomalously robust valley polarization and valley coherence in bilayer WS2. The polarization of the photoluminescence from bilayer WS2 follows that of the excitation source with both circular and linear polarization, and remains even at room temperature. The near-unity circular polarization of the luminescence reveals the coupling of spin, layer, and valley degree of freedom in bilayer system, and the linearly polarized photoluminescence manifests quantum coherence between the two in-equivalent band extrema in momentum space, namely, the valley quantum coherence in atomically thin bilayer WS2. This observation provides insight into quantum manipulation in atomically thin semiconductors.

• 出版日期2014-8-12
• 单位南方科技大学