Control State Transfer In A Heisenberg Spin Chain By Periodic Drives

In recent years,people gradually understood the advantages of quantum communication and quantum computing,and more and more scholars enter this field.This field has developed into one of the most dynamic areas of research with extensive related articles.Quantum communication mainly includes quantum dense encoding,quantum teleportation,quantum secret sharing and so on.Quantum communication uses quantum characteristics to establish key between sender and receiver.Entanglement is different from classical communication in quantum encryption.Quantum Computing mainly uses short-range transmission of quantum information.In fact,unlike classical information,the information inside a quantum computer is carried by quantum states.The isotropic Heisenberg spin chain proposed by S.Bose can be used to realize short distance transmission of quantum states.Because spin chains have good compatibility and easy to manipulate,scholars have proposed many different schemes of quantum state transmission in spin models.In this paper,we propose a state transfer and blockade scheme based on Heisenberg spin chain.In this scheme,the periodic drive of the system is used to control the state transmission.Using XXZ Heisenberg spin chain,the scheme achieves perfect state transmission between input and output ports,when there is no periodic drive in the system.Taking four particles as an example,we expand the Hamiltonian under the coupling basis vector to get the diagonal Hamiltonian matrix,and calculate the analytical solution of perfect state transmission,that is,the condition of perfect state transmission.Periodic driving blocks the transmission of any spin state between the input and output ports.In this paper,we add three kinds of driving to achieve complete blocking of state transmission.It is found that the effective interaction coefficients of the system will change when the form of added driving changes.Secondly,considering the influence of system parameter fluctuation,we simulate the transmission and interruption fidelity of the system.Furthermore,we use random Hamiltonian to simulate the influence of classical noise on quantum system,and explore the influence of decoherence on the transmission of quantum states.Finally,we study the case of N particles and give some discussions and conclusions.