# Asymptotic Convertibility of Entanglement: A General Approach to Entanglement Concentration and Dilution

## TL;DR

This paper develops a general framework for understanding the asymptotic convertibility of bipartite pure states via LOCC, using an information-spectrum approach to handle non-i.i.d. sequences and deriving conditions based on spectral entropy rates.

## Contribution

It introduces a novel information-spectrum method to characterize LOCC convertibility for arbitrary pure state sequences, extending previous results on entanglement concentration and dilution.

## Key findings

- Derived necessary and sufficient conditions for LOCC convertibility.
- Provided simplified proofs for optimal entanglement concentration and dilution rates.
- Extended the theory to non-i.i.d. sequences of pure states.

## Abstract

We consider asymptotic convertibility of an arbitrary sequence of bipartite pure states into another by local operations and classical communication (LOCC). We adopt an information-spectrum approach to address cases where each element of the sequences is not necessarily in tensor power of a bipartite pure state. We derive necessary and sufficient conditions for the LOCC convertibility of one sequence to another in terms of spectral entropy rates of entanglement of the sequences. Based on these results, we also provide simple proofs for previously known results on the optimal rates of entanglement concentration and dilution of general sequences of pure states.