中国物理B ›› 2020, Vol. 29 ›› Issue (8): 84102-084102.doi: 10.1088/1674-1056/ab96a9

• SPECIAL TOPIC—Ultracold atom and its application in precision measurement • 上一篇    下一篇

Electromagnetic field of a relativistic electron vortex beam

Changyong Lei(雷长勇), Guangjiong Dong(董光炯)   

  1. 1 State Key Laboratory of Precision Spectroscopy, School of Physics and Electronics, East China Normal University, Shanghai 200241, China;
    2 Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
  • 收稿日期:2020-02-25 修回日期:2020-04-05 出版日期:2020-08-05 发布日期:2020-08-05
  • 通讯作者: Guangjiong Dong E-mail:gjdong@phy.ecnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11574085, 91536218, and 11834003), the 111 Project, China (Grant No. B12024), the National Key Research and Development Program of China (Grant No. 2017YFA0304201), and the Innovation Program of Shanghai Municipal Education Commission, China (Grant No. 2019-01-07-00-05-E00079).

Electromagnetic field of a relativistic electron vortex beam

Changyong Lei(雷长勇)1, Guangjiong Dong(董光炯)1,2   

  1. 1 State Key Laboratory of Precision Spectroscopy, School of Physics and Electronics, East China Normal University, Shanghai 200241, China;
    2 Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
  • Received:2020-02-25 Revised:2020-04-05 Online:2020-08-05 Published:2020-08-05
  • Contact: Guangjiong Dong E-mail:gjdong@phy.ecnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11574085, 91536218, and 11834003), the 111 Project, China (Grant No. B12024), the National Key Research and Development Program of China (Grant No. 2017YFA0304201), and the Innovation Program of Shanghai Municipal Education Commission, China (Grant No. 2019-01-07-00-05-E00079).

摘要: Electron vortex beams (EVBs) have potential applications in nanoscale magnetic probes of condensed matter and nanoparticle manipulation as well as radiation physics. Recently, a relativistic electron vortex beam (REVB) has been proposed[Phys. Rev. Lett. 107 174802 (2011)]. Compared with EVBs, except for orbital angular momentum, an REVB has intrinsic relativistic effect, i.e., spin angular momentum and spin-orbit coupling. We study the electromagnetic field of an REVB analytically. We show that the electromagnetic field can be separated into two parts, one is only related to orbital quantum number, and the other is related to spin-orbit coupling effect. Exploiting this separation property, the difference between the electromagnetic fields of the REVB in spin-up and spin-down states can be used as a demonstration of the relativistic quantum effect. The linear momentum and angular momentum of the generated electromagnetic field have been further studied and it is shown that the linear momentum is weakly dependent on the spin state; while the angular momentum is evidently dependent on the spin state and linearly increases with the topological charge of electron vortex beam. The electromagnetic and mechanical properties of the REVB could be useful for studying the interaction between REVBs and materials.

关键词: relativistic electron vortex beam, electromagnetic vortex field, spin-orbit coupling, orbital angular momentum

Abstract: Electron vortex beams (EVBs) have potential applications in nanoscale magnetic probes of condensed matter and nanoparticle manipulation as well as radiation physics. Recently, a relativistic electron vortex beam (REVB) has been proposed[Phys. Rev. Lett. 107 174802 (2011)]. Compared with EVBs, except for orbital angular momentum, an REVB has intrinsic relativistic effect, i.e., spin angular momentum and spin-orbit coupling. We study the electromagnetic field of an REVB analytically. We show that the electromagnetic field can be separated into two parts, one is only related to orbital quantum number, and the other is related to spin-orbit coupling effect. Exploiting this separation property, the difference between the electromagnetic fields of the REVB in spin-up and spin-down states can be used as a demonstration of the relativistic quantum effect. The linear momentum and angular momentum of the generated electromagnetic field have been further studied and it is shown that the linear momentum is weakly dependent on the spin state; while the angular momentum is evidently dependent on the spin state and linearly increases with the topological charge of electron vortex beam. The electromagnetic and mechanical properties of the REVB could be useful for studying the interaction between REVBs and materials.

Key words: relativistic electron vortex beam, electromagnetic vortex field, spin-orbit coupling, orbital angular momentum

中图分类号:  (Beam optics)

  • 41.85.-p
42.50.Tx (Optical angular momentum and its quantum aspects) 03.65.Pm (Relativistic wave equations)