The Theoretical Study Of Quantum Speed Limit Under Squeezed Reservoir

It is called quantum speed limit time for the shortest time from the initial state to its orthogonal final state in the closed unitary evolution.In the realistic quantum information processing,the quantum system will inevitably interacts with the surrounding environment,and the corresponding system is called quantum open system.The concept of quantum speed limit has also been extended to quantum open system,and the effects of the environment on the quantum speed limit had been widely concerned.In the quantum information processing,the squeezed state and squeezed environment are important quantum resources.However,the study of quantum speed limit under the interaction between the quantum system and the squeezed environment has not been reported.In this thesis,the effects of squeezed environment on the quantum speed limit are studied by using two typical theoretical models,i.e.,the damped Jaynes-Cummings model and the dephasing model.The contents are as follows:For the damped Jaynes-Cummings model under squeezed reservoir,the analytical solution of quantum speed limit for system under the squeezed reservoir is derived,the quantum speed limit bound will be sharper along with the increase of squeezed parameter r.The quantum speed limit time indicates symmetrical distribution about the phase parameters?=?,and the appropriate phase parameter can accelerate the evolution of quantum states under squeezed reservoir.In addition,the quantum speed limit time can also be affected by the coupling strength between the quantum system and surrounding environment.In the dephasing model under squeezed reservoir,the analytical solution of quantum speed limit for system under the squeezed reservoir is derived,the quantum speed limit time is determined by the dephasing rate and the boundary of acceleration region that interacting with vacuum reservoir can be broken when the squeezed environment parameters are appropriately chosen.