Giant effective Zeeman splitting in a monolayer semiconductor realized by spin-selective strong light-matter coupling
Giant effective Zeeman splitting in a monolayer semiconductor realized by spin-selective strong light-matter coupling
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DOI：
10.1038/s41566-022-01025-8
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发表时间：
2022-07-07
期刊：
影响因子：
35
通讯作者：
Tartakovskii, A. I.
中科院分区：
文献类型：
--
作者：
Lyons, T. P.;Gillard, D. J.;Tartakovskii, A. I.
光与二维电子气（2DEG）的基本激发之间的强耦合对于纯物理学和未来光子纳米技术的理解和发展都具有基础性的重要性（1-7）。在这里，我们研究了单层半导体，MoSe 2中的2DEG的自旋极化和零维光学微腔修改的光-物质相互作用之间的关系。我们发现显着的自旋磁化率的2DEG同时增强和抑制三重极化激元形成相反的光子螺旋。这导致观察到一个巨大的有效谷塞曼分裂的三振子极化激元（g因子>20），超过纯三振子分裂超过五倍。更进一步，我们观察到明确的有效的光学非线性所产生的高度非线性行为的山谷特定的强光-物质耦合制度，并允许全光调谐的极化塞曼分裂从4 meV到>10 meV。我们的实验奠定了工程拓扑相位与真正的单向性在单层半导体，伴随着巨大的有效光子非线性植根于多体激子-电子相关性。
Strong coupling between light and the fundamental excitations of a two-dimensional electron gas (2DEG) is of foundational importance both to pure physics and to the understanding and development of future photonic nanotechnologies(1-7). Here we study the relationship between spin polarization of a 2DEG in a monolayer semiconductor, MoSe2, and light-matter interactions modified by a zero-dimensional optical microcavity. We find pronounced spin-susceptibility of the 2DEG to simultaneously enhance and suppress trion-polariton formation in opposite photon helicities. This leads to observation of a giant effective valley Zeeman splitting for trion-polaritons (g-factor of >20), exceeding the purely trionic splitting by over five times. Going further, we observe clear effective optical nonlinearity arising from the highly nonlinear behaviour of the valley-specific strong light-matter coupling regime, and allowing all-optical tuning of the polaritonic Zeeman splitting from 4 meV to >10 meV. Our experiments lay the groundwork for engineering topological phases with true unidirectionality in monolayer semiconductors, accompanied by giant effective photonic nonlinearities rooted in many-body exciton-electron correlations.