论文标题
在2D钙钛矿中调整浆果曲率
Tuning the Berry curvature in 2D Perovskite
论文作者
论文摘要
拓扑物理学，尤其是它与人造量规场的联系是不同物理系统中的一个最前沿的话题，从冷原子到光子学以及最近的半导体装饰的激子 - photon状态，称为Polaritons。通过纳米化或利用固有材料和腔各向异性，在微腔内工程偏振子的能量分散表现出了许多与拓扑结构和新兴仪表领域有关的有趣效果。在这里，我们表明我们可以控制在强耦合有机无机2D Perovskite单晶中极化带的浆果曲率分布。钙钛矿晶体的空间各向异性与光子自旋轨道耦合相结合，使得在分散体中出现了两个汉密尔顿的恶魔般的点。由于激子Zeeman分裂，外部磁场的应用破坏了时间逆转对称性。它分解了恶魔点的变性。最终的谱带显示非零的积分浆果曲率，我们通过状态断层扫描直接测量。至关重要的是，我们表明我们可以在相同的微腔内控制带中所谓的带状几何形状中的浆果曲率分布。
Topological physics and in particular its connection with artificial gauge fields is a forefront topic in different physical systems, ranging from cold atoms to photonics and more recently semiconductor dressed exciton-photon states, called polaritons. Engineering the energy dispersion of polaritons in microcavities through nanofabrication or exploiting the intrinsic material and cavity anisotropies has demonstrated many intriguing effects related to topology and emergent gauge fields. Here, we show that we can control the Berry curvature distribution of polariton bands in a strongly coupled organic-inorganic 2D perovskite single crystal. The spatial anisotropy of the perovskite crystal combined with photonic spin-orbit coupling make emerge two Hamilton's diabolical points in the dispersion. The application of an external magnetic field breaks time reversal symmetry thanks to the exciton Zeeman splitting. It splits the diabolical points degeneracy. The resulting bands show non-zero integral Berry curvature which we directly measure by state tomography. Crucially, we show that we can control the Berry curvature distribution in the band, the so-called band geometry, within the same microcavity.
