Quantum Teleportation And Weak Measurement In Noninertial Frame

In recent years, the theory of quantum information in a relativistic setting, which is the integration of the classic information, quantum mechanics, special and general relativity, and quantized field theory, becomes the hot spot of the research of the quantum information. This thesis is devoted to the investigation of the teleportation and the question on the weak measurement in the theory of quantum information in a relativistic setting.The quantum teleportation between two relatively accelerated partners undergoing the phase flip, bit flip, and bit-phase flip channels is studied. We show that the fidelity of the teleportation depends on the acceleration pa-rameter r, environment parameter p and transmitted state parameter β. By fixing p and β, the fidelity is consistently decreases with the increase of the acceleration. However, by fixing r, the dynamic evolution of the fidelity has different properties, which are listed in detail as follows:(i) For the phase flip channel, the fidelity is monotonously reduced as p increases. When β2=1/2, the fidelity will converge to F=182after a long time of the interaction be-tween the system and the environment;(ii) For the bit flip channel, when β2=1/2, the fidelity of the teleportation is not affected by the environment at all. But when β2≠1/2, the fidelity will emerge a turning point at the p axis. Before the point the fidelity decreases monotonously and after that the fidelity increases monotonously. However, the fidelity decreases all the time if Rob is not accelerated. It should be noted out that, provided r is chosen appropriately, the fidelity can increase monotonously with the increase of p when β2∈(1/4,1/2)∪(1/2,3/4); And (iii) for the phase-bit channel, all the fidelities converge to one point F=1/2for any acceleration and any transmission state parameter β if the time of the interaction between the system and the environ-ment is long enough. The fidelity is also monotonously decreasing when β2=1/2or the acceleration is zero in this channel. In addition to that, undergoing any of the three environment the fidelity is always symmetric about β2=1/2as it is a function of the transmission state parameter β. And it, as β2=0or β2=1, is constant for the phase flip channel, while it is constant with β2=1/2for the bit flip channel, which indicates that there are the different characters between these environments.By investigating the quantum correlations based on the weak measure-ment in noninertial frame we study the properties and inconsistence of the quantum discord and geometric discord. We find that:(i) using the weak measurement to define the quantum discord we can capture more quantum correlations and obtain a super quantum discord. However, using the weak measurement to define the geometric discord we note that the quantity be-comes smaller and results in a inferior "geometric discord";(ii) with the in-crease of the observer’s acceleration, both the super quantum discord and the inferior "geometric discord" decrease monotonously; and (iii) as the measure-ment strength increases, the super quantum discord decreases monotonously, and finally goes back to the normal quantum discord when the strength param-eter, x, approaches to the infinity. However, the inferior "geometric discord" increases with the increase of the measurement strength, also goes back to the normal geometric discord when x—∞. Different properties of the quantum and the geometric discords based on the weak measurement show us that these two "discords" have completely different reactions to the change of the mea-surement strength. So, in some sense, we can say that these differences are the evidences to prove the inconsistence between the quantum discord and the geometric discord.