# Optimal and covariant single-copy LOCC transformation between two two-qubit states

Source: [Optimal and covariant single-copy LOCC transformation between two two-qubit states](<https://www.sota2.com/research/paper/68fa31e51e209131ce883421>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T19:10:38.962Z

Authors: K. Bradler

Published: 2006-11-09T22:37:01.000Z

## Abstract

Given two two-qubit pure states characterized by their Schmidt numbers we investigate an optimal strategy to convert the states between themselves with respect to their local unitary invariance. We discuss the efficiency of this transformation and its connection to LOCC convertibility properties between two single-copy quantum states. As an illustration of the investigated transformations we present a communication protocol where in spite of all expectations a shared maximally entangled pair between two participants is the worst quantum resource.

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/quant-ph/0611107>)

[PDF](<https://arxiv.org/pdf/quant-ph/0611107.pdf>)