Einstein-Podolsky-Rosen correlation in Kerr-Newman spacetime

The EPR correlation has become an integral part of quantum communications as has general relativity in classical communication theory, however when combined an apparent deterioration is observed for spin states. We consider appropriate changes in directions of measurement to exploit full EPR entanglement for a pair of particles and show that it can be deduced only up to the outer event horizon of a Kerr-Newman black hole, even in the case of a freely falling observer.

Figure 1

The infinitesimal LLT for a Kerr-Newman black hole with parameters $M=1000$, $a=0.8M$, $Q=0.2M$, and $v=0.3$,0.5, 0.7, and 0.9 for the black, thick, dashed, and thick dashed lines, respectively.

Figure 2

The rotation angle for a Kerr-Newman black hole with parameters $M=1000$, $a=0.8M$, and $Q=0.2M$ for the figure on the left and, $M=1000$, $a=0.9M$, and $Q=0.1M$ for the one on the right, and both with $v=0.3$, 0.5, 0.7, and 0.9 for the black, thick, dashed, and thick dashed lines, respectively.

Figure 3

The EPR setup in the Kerr-Newman spacetime. Gray circles are the observers and the gray square is the EPR source.