碳纳米管中激光驱动的携带有轨道角动量的电子发射
Laser-Driven Electron Emission Carrying Orbital Angular Momentum from Carbon Nanotubes
- Hefei University of Technology（合肥工业大学）
- Nanjing University of Science and Technology（南京理工大学）
- The University of Hong Kong（香港大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文通过含时密度泛函理论证明，激光驱动的扶手椅型碳纳米管可发射携带有轨道角动量的慢电子，且电离产额和OAM显著高于CO2和苯，管径和脉冲螺旋度可调控发射特性。
AI中文摘要：
将轨道角动量（OAM）自由度扩展到慢电子，将开启低能电子-物质相互作用的一个独特领域。利用含时密度泛函理论，我们证明了激光驱动的扶手椅型碳纳米管（CNTs）能够发射携带有OAM的慢电子。一束圆偏振的OAM写入脉冲促进环向电子运动，并产生围绕管轴的OAM；一束延迟的线偏振提取脉冲释放出携带注入角动量的慢电子。我们发现，在相同的激光条件下，代表性CNTs的电离产额和净发射轴向OAM远高于取向的CO2和苯。增加管径显著提高了电离产额和OAM，此外，反转OAM写入脉冲的螺旋度会翻转发射OAM的符号。这些发现共同确立了CNTs作为具有光学可控OAM的慢电子发射平台。
英文摘要：
Extending the orbital angular momentum (OAM) degree of freedom to slow electrons would open a distinct regime of low-energy electron-matter interactions. Using time-dependent density-functional theory, we demonstrate that laser-driven armchair carbon nanotubes (CNTs) can emit OAM-carrying slow electrons. A circularly polarized OAM-writing pulse promotes circumferential electronic motion and generates OAM about the tube axis; a delayed linearly polarized extraction pulse releases slow electrons carrying the injected angular momentum. We find much higher ionization yields and net emitted axial OAM in representative CNTs than in oriented CO2 and benzene under identical laser conditions. Increasing the tube diameter enhances the ionization yield and OAM substantially, and moreover, reversing the helicity of the OAM-writing pulse flips the sign of the emitted OAM. Together, these findings establish CNTs as a platform for slow-electron emission with optically controllable OAM.
