Multipartite Entanglement In Noninertial Frames

People have done a lot of research on quantum information of inertial system,a more complete theory of quantum information is established;And entanglement plays an im-portant role in quantum information theory,it is believed to be the main resource of quan-tum information processing tasks.It is now used in quantum information processing ex-periments are very large number of photons or particles,and the world we’re in now is spinning and accelerating,so we have to consider the effect of relativistic effects on our experiments.What’s more,with the combination of quantum theory and general relativ-ity and quantum field theory is closely,so it is very important to study the multipartite entanglement in the framework of the theory of relativity.Firstly,based on the noninertial system of two particle entangled state,we use the same method to study three particle entangled state varies with observer’s acceleration.After calculation,we found that three particle entanglement decreases with the increase of ob-server’s acceleration.What’s more,the entanglement decreases much quicker when three observers are all accelerate.But it does not decay to zero in the case of the accelera-tion to infinity.And the physical properties are established both for Scalar field and Dirac field.However,when the observer’s acceleration approach infinity,the entanglement of two particles in the scalar field does not decay to zero in the noninertial frames,therefore we believe that in the quantum information processing tasks with three particle entanglement will be more superior than the two particle entanglement.Secondly,we also study the distribution of quantum information,the physical acces-sible entanglement degrades while the inaccessible entanglement increases quickly.From this we can known that the decrease of the quantum entanglement in the noninertial sys-tem is due to the Unruh effect and the entanglement from Ⅰ region to Ⅱ region,as the entanglement was leaked into the causally disconnected region.And the entanglement de- cay quickest when three observers accelerate,this is due to the entanglement redistributed to the unaccessible region at a faster speed.Finally,we study the mutual information and fidelity,and find that not only is the entanglement redistributed.but also the mutual information is distributed to the physi-cal inaccessible region,the quantum information will not disappear without reason.And also the fidelity decreases with the increase of the observer’s acceleration.The fidelity decreases quickest when three observers are all accelerate,this means that the fidelity in conventional teleportation protocol is related to the entanglement.