2010/08/05 by Chun-Fang Li, Yan Wang, Li, Chun-Fang +1
Chemistry · Engineering · Materials Science · Mathematics · Physics and Astronomy · #Chemistry #Condensed matter physics #Electron #Electron and X-Ray Spectroscopy Techniques #FOS: Physical sciences #Mathematics #Mathematics education #Photocathodes and Microchannel Plates #Physics #Polarization (electrochemistry) #Quantum Physics (quant-ph) #Quantum mechanics #Spin polarization #Unit (ring theory) #quant-ph
paper · pdf · doi:10.48550/arxiv.1008.0924
14 pages with 1 figure. This article was submitted to Phys. Rev. A on May 11, 2010 and was presented as an invited talk in workshop "Spintronics Days" at UPV-EHU (2010), held at Bilbao, Spain during July 27-28, 2010
arxiv created 2010/08/05 · openalex publication_date 2010/08/05 · arxiv updated 2010/08/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
New degrees of freedom having the form of a unit vector are identified for characterizing the spin polarization of free electron. It is shown that when only the spin is considered, the non-commutativity of the Cartesian components of the Pauli vector allows us to use the azimuthal angle of a second direction, denoted by unit vector \mathbf I, with respect to the quantization direction to characterize the spin polarization. The rotation of \mathbf I through an angle about the quantization axis leads to a rotation of the spin polarization vector through twice the angle about the same axis. Discussions are also made in Heisenberg picture as well. Upon utilizing this approach to a free electron and letting the quantization direction for each plane wave be the wave vector, we arrive at a representation in which the unit vector \mathbf I functions as an independent index to characterize the spin polarization.