Research On The Non-Markovian Environmental Dynamics Evolution Characteristics Of Various Quantum Correlations In Solid Systems Such As Double Quantum Dots

The field of quantum information has achieved unprecedented development.Quantum correlations are core resource of quantum information processing.However,any physical system that realizes quantum correlation is inevitably coupled with the surrounding environment.Under this kind of coupling,it is difficult for a physical system to maintain quantum properties such as quantum correlation.Therefore,in the related research on the dynamic evolution of open quantum systems,how to preserve the quantum correlation of the system for a long time and restrain its decoherence behavior has always been a problem to be solved.In the study of dynamic evolution of open quantum systems,the environment around the quantum system is usually regarded as a Markovian environment without memory effect.However,in many physical systems such as solid-state systems,the environment around quantum systems has a memory effect,and such systems must be described by non-Markovian processes.In this thesis,we use the non-Markov quantum state diffusion method to study the non-Markovian dynamic evolution characteristics of the quantum correlation of solid-state quantum systems such as double quantum dots.This thesis is divided into four chapters.The first chapter summarizes the research background and significance of this thesis and introduces the measurement methods of quantum correlation and quantum teleportation fidelity.In the second chapter,the basic principles of open quantum systems and non-Markovian quantum state diffusion methods are introduced.In the third chapter,apply the non-Markovian quantum state diffusion theory study the fidelity of quantum teleportation with a single two-level atom and a single three-level atom as the channel is first studied using this theory.Studies have shown that quantum teleportation can maintain high channel fidelity for a long time in a strong non-Markov environment.In addition,studies have shown that an external magnetic field can protect the fidelity of the channel.Secondly,the non-Markovian dynamic evolution characteristics of the quantum coherence of the Heisenberg XXZ spin model are studied.Studies have shown that the quantum coherence of this model is a good quantum resource just like quantum entanglement and quantum detuning in a non-Markovian environment.And the internal coupling parameters of the spin chain can be used to keep the quantum coherence near the ideal value for a long time.In the fourth chapter,the quantum correlation dynamics evolution characteristics of the double quantum dot system in the zero temperature and non-zero temperature non-Markovian environment are studied.The calculation results show that the environmental memory time has a positive effect on the various quantum correlations of the double quantum dot charge bits.The thermal motion of the electrons in the library will damage the non-Markovian characteristics of the environment.Therefore,the quantum entanglement,quantum discord,and geometric quantum discord changes with time are more ideal at lower temperatures.