2011/11/30 by Pablo L. Saldanha, Vlatko Vedral · 51 citations
Computer Science · Physics and Astronomy · #Context (archaeology) #Density matrix #Field (mathematics) #Interpretation (philosophy) #Mechanical and Optical Resonators #Pauli exclusion principle #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Spin (aerodynamics) #Theoretical physics #quant-ph
paper · pdf · doi:10.1088/1367-2630/14/2/023041
published in New Journal of Physics 14(2), 023041 (IOP Publishing) · 10 pages, 2 figures. Several changes were made on the text. One extra example was included
openalex publication_date 2012/02/20 · arxiv created 2012/02/25 · arxiv updated 2012/02/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We present a new treatment for the spin of a massive relativistic particle in the context of quantum information based on a physical interpretation of the Wigner rotations, obtaining different results in relation to previous works. We are led to the conclusion that it is not possible to define a reduced density matrix for the particle spin and that the Pauli–Lubanski (or similar) spin operators are not suitable for describing measurements where the spin couples to an electromagnetic field in the measuring apparatus. These conclusions contradict the assumptions made by most of the previous papers on the subject. We also propose an experimental test of our formulation.