Abstract
We theoretically propose a dense coding scheme based on an infinite spin-1/2 Ising-XXZ diamond chain, where the Heisenberg spins dimer can be considered as a quantum channel. Using the transfer-matrix approach, we can obtain the analytical expression of the optimal dense coding capacity chi. The effects of anisotropy, external magnetic field, and temperature on chi in the diamond-like chain are discussed, respectively. It is found that chi is decayed with increasing the temperature, while the valid dense coding (chi > 1) can be carried out by tuning the anisotropy parameter. Additionally, a certain external magnetic field can stimulate the enhancement of dense coding capacity. In an infinite spin-1/2 Ising-XXZ diamond chain, it has been shown that there exist two kinds of quantum phase transitions (QPTs) in zero-temperature phase diagram, i.e., one is that the ground state of system changes from the unentangled ferrimagnetic state to the entangled frustrated state and the other is from the entangled frustrated state to the unentangled ferromagnetic state. Here, we propose that optimal dense coding capacity chi can be regarded as a new detector of QPTs in this diamond-like chain, and the relationship between chi and QPTs is well established. (C) 2021 Elsevier B.V. All rights reserved.
NSTL
Elsevier