Quantum communication through anisotropic Heisenberg XY spin chains

TL;DR

This paper investigates quantum state transfer in anisotropic Heisenberg XY spin chains, highlighting regimes where high fidelity and entanglement can be achieved for practical quantum communication.

Contribution

It analyzes how anisotropy and magnetic field strength influence quantum fidelity and entanglement in spin chains, identifying optimal conditions for quantum communication.

Findings

High fidelity transfer possible at specific times and anisotropy levels

Strong magnetic fields reduce anisotropy effects on fidelity

Increased anisotropy enhances entanglement generation

Abstract

We study quantum communication through an anisotropic Heisenberg XY chain in a transverse magnetic field. We find that for some time $t$ and anisotropy parameter $\gamma$, one can transfer a state with a relatively high fidelity. In the strong-field regime, the anisotropy does not significantly affect the fidelity while in the weak-field regime the affect is quite pronounced. The most interesting case is the the intermediate regime where the oscillation of the fidelity with time is low and the high-fidelity peaks are relatively broad. This would, in principle, allow for quantum communication in realistic circumstances. Moreover, we calculate the purity, or tangle, as a measure of the entanglement between one spin and all the other spins in the chain and find that the stronger the anisotropy and exchange interaction, the more entanglement will be generated for a given time.