Transfer of 0-order coherence matrix along spin-1/2 chain

TL;DR

This paper investigates the perfect transfer of 0-order coherence matrices along spin-1/2 chains, highlighting the role of extended receivers and unitary transformations to optimize transfer fidelity, especially for long chains.

Contribution

It introduces a method for perfect transfer of 0-order coherence matrices using extended receivers and optimization, including asymptotic analysis for infinitely long chains.

Findings

Perfect transfer of 0-order coherence matrices is achievable with proper fixing of elements.

Extended receivers and optimized unitary transformations improve transfer fidelity.

Asymptotic analysis shows the behavior of transfer deviation for long chains.

Abstract

In this work, we study transfer of coherence matrices along spin-1/2 chains of various length. Unlike higher order coherence matrices, 0-order coherence matrix can be perfectly transferred if its elements are properly fixed. In certain cases, to provide the perfect transfer, an extended receiver together with optimized its unitary transformation has to be included into the protocol. In this work, the asymptotic perfectly transferable 0-order coherence matrix for an infinitely long chain is considered and deviation of a perfectly transferred state from this asymptotic state is studied as a function of the chain length for various sizes of the extended receiver. The problem of arbitrary parameter transfer via the nondiagonal elements of the 0-order coherence matrix is also considered and optimized using the unitary transformation of the extended receiver.