English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

New degrees of freedom having the form of a unit vector are identified forcharacterizing the spin polarization of free electron. It is shown that whenonly the spin is considered, the non-commutativity of the Cartesian componentsof 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 directionto characterize the spin polarization. The rotation of $\mathbf I$ through anangle about the quantization axis leads to a rotation of the spin polarizationvector through twice the angle about the same axis. Discussions are also madein Heisenberg picture as well. Upon utilizing this approach to a free electronand 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 asan independent index to characterize the spin polarization.

A unit vector for characterizing the spin polarization of free electron