Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-momentum correlation in relativistic single particle quantum states   This paper was concerned with the spin-momentum correlation in
single-particle quantum states, which is described by the mixed states under
Lorentz transformations. For convenience, instead of using the superposition of
momenta we use only two momentum eigen states (p1 and p2) that are
perpendicular to the Lorentz boost direction. Consequently, in 2D momentum
subspace we show that the entanglement of spin-momentum in the moving frame
depends on the angle between them. Therefore, when spin and momentum are
perpendicular the measure of entanglement is not observer-dependent quantity in
inertial frame. Likewise, we have calculated the measure of entanglement (by
using the concurrence) and has shown that entanglement decreases with respect
to the increasing of observer velocity. Finally, we argue that, Wigner rotation
is induced by Lorentz transformations can be realized as controlling operator.

29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int