发表机构
Nanyang Technological University; School of Electrical and Electronics Engineering, Nanyang Technological University; Centre of Disruptive Photonics Technologies, School of Physical and Mathematical Sciences（南洋理工大学; 南洋理工大学电气与电子工程学院; 物理与数学学院破坏性光子技术研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究构建了自由电子时空波包，利用其独特色散实现可调斯格明子纹理与拓扑相变，为拓扑电子波包在传感和信息传输中的应用提供新平台。
AI 中文摘要
时空波包（STWPs）已在光学领域中实现了许多非平凡性质，如可调群速度、无衍射和非局域自旋纹理。然而，这在物质波中尚未得到适当研究。在此，我们研究了自由电子STWPs，它们是通过在动量空间中约束电子波函数的时空谱而构建的传播不变且群速度可调的物质量波包。由于自由电子的独特色散关系，电子STWP可以携带两种不同的拓扑结构，并在动量空间中拥有meron和斯格明子拓扑纹理。我们通过谱几何调谐展示了拓扑相变和可调斯格明子数。我们还展示了电子脉冲的拓扑鲁棒传播以及编码在每个单电子波函数内的相应实空间斯格明子期望值纹理。我们的结果为拓扑自由电子波包在传感和信息传输中的应用开辟了一个平台。
英文摘要
Space-Time Wave Packets (STWPs) have enabled numerous nontrivial properties, such as tunable group velocities, nondiffraction and nonlocal spin textures in optical fields. However, this has not been properly studied in matter waves. Here, we investigate free-electron STWPs, which are propagation-invariant and group-velocity-tunable matter wave packets, constructed by constraining the spatiotemporal spectrum of the electron wavefunction in momentum space. Due to the unique dispersion of free-electrons, the electron STWP can carry two different topologies, and host both meron and skyrmion topological textures in momentum space. We demonstrate the topological phase transitions and tunable skyrmion numbers by spectral geometry tuning. We also show the topologically robust propagation of the electron pulses and corresponding real-space skyrmionic expectation value textures encoded within each single electron wavefunction. Our results open a platform for topological free-electron wavepackets uses in sensing and information transfer.
