Quantum entanglement in spin chains with the XY Hamiltonian at the quantum state transfer

摘要

In the present work the generation of entanglement between the receiver and sender is investigated in the processof the quantum state transfer in the homogeneous one-dimensional chain of spins 1/2 with the XY -Hamiltonianin the approximation of the nearest neighbour interactions. Fidelity is obtained for a quantum state transfer forvarious numbers of spins and temperatures and values of initial polarisation of the sender’s spin. The transmittedpure state is encoded in the state of first spin (sender) in the initial time moment. The other spins are in thethermodynamic equilibrium state. The reduced density matrix for the receiver and the sender is obtained for aninvestigation of entanglement in the "sender-receiver" system. The effect of temperature and polarization of thetransmitted state on the generation of entanglement in the system is also investigated.