Influence Of Memory Effects Of Different Baths On Quantum Communication In Solid State Systems Such As Double Quantum Dots

Quantum information science is an emerging interdisciplinary subject,covering a wide range of disciplines such as quantum mechanics and quantum optics.In recent years,with the improvement of human science and technology,many theoretical solutions in quantum information science have been realized in reality,such as quantum teleportation,quantum dense coding and quantum key transmission.The quantum teleportation theory scheme has attracted the interest of physicists and experimental physicists since it was proposed by Bennet et al.in 1993.Quantum teleportation can use two entangled particles and local operations.The unknown quantum state is superior to the fidelity transmitter of any classical protocol,which is implemented in photon bits and atomic bits.So far,quantum teleportation has been implemented in many different systems,including quantum dot systems,superconducting quantum circuits,ion trap systems,optical systems,and nuclear magnetic resonance systems.Among them,solid-state quantum systems have the characteristics of easy integration and scalability,and have potential application value in quantum communication and information processing(such as quantum teleportation).This thesis is divided into four chapters.The first chapter briefly reviews the development of quantum information science and the purpose and significance of the topic.The second chapter introduces the basic concept of open quantum system,expounds the non-Markovian quantum state diffusion method and the research status at home and abroad.The basic theory of quantum information includes the theoretical basic knowledge of quantum teleportation and quantum dense coding.In the third chapter,the quantum state diffusion method is used to study the dynamic evolution of quantum teleportation average fidelity when the two-bit Heisenberg mode XXZ spin chain system interacts with the zero-temperature Bose library,and the standard quantum invisibility is given.The model uses the model to pass the average fidelity of a single qubit state with the variation of each parameter.According to the evolutionary image,it can be seen that under the standard quantumteleportation protocol,when the equivalent subchannel is in the maximum entangled state,the non-Markov effect plays a positive role in improving the average fidelity of quantum teleportation by adjusting the two bits.The inter-coupling constant and proper transmission time increase the uniform magnetic field strength or DM interaction to obtain the optimal average fidelity.In the fourth chapter,the quantum state diffusion method is used to study the dynamics of quantum teleportation average fidelity and dense coded channel capacity when the coupled double quantum dot system interacts with zero-temperature Fermi library.The calculation results show that the non-Markov environmental noise coefficient and the double quantum dot coupling coefficient play a positive role in the quantum teleportation mean fidelity and dense coded channel capacity.In addition,when the quantum channel is in the isolated state,the channel capacity value is the largest,and The maximum channel capacity value can be reached at a special point.The fifth chapter summarizes and forecasts the work of graduate students for three years.