Depurification by Lorentz boosts
arXiv:quant-ph/0310145 · doi:10.1016/j.physleta.2004.07.001
Abstract
We consider a particle of half-integer spin which is nonrelativistic in the rest frame. Assuming the particle is completely polarized along third axis we calculate the Bloch vector as seen by a moving observer. The result for its length is expressed in terms of dispersion of some vector operator linear in momentum. The relation with the localization properties is discussed.
5 pages