Complete structural restoring of transferred multi-qubit quantum state

TL;DR

This paper presents a universal protocol for perfectly restoring the multi-quantum coherence matrices of multi-qubit states transferred through a spin chain, using a specially designed unitary transformation.

Contribution

It introduces a universal restoring protocol and a method for constructing a perfectly transferable 0-order coherence matrix in quantum spin chains.

Findings

The restoring protocol is universally optimal for any chain length.

It enables perfect transfer of the 0-order coherence matrix.

The method applies to reconstruct higher-order coherence matrices.

Abstract

We develop the protocol for structural restoring of multi-quantum coherence matrices of the multi-qubit quantum state transferred from the sender to the receiver along a spin-1/2 chain. We also propose a protocol for constructing such 0-order coherence matrix that can be perfectly transferred in this process. The restoring protocol is based on the specially constructed unitary transformation of the extended receiver.{This transformation for a given length parameters of the chain is universally optimal in the sense that ones constructed it can be applied to optimally restore any higher-order coherence matrices.