Nonlocality distillation can outperform entanglement distillation

TL;DR

This paper compares entanglement and nonlocality distillation strategies, showing that nonlocality distillation can outperform entanglement distillation in certain scenarios, especially with fewer copies, offering better resource efficiency.

Contribution

It demonstrates that nonlocality distillation can surpass entanglement distillation in CHSH violation, particularly with limited copies, challenging the conventional focus on entanglement.

Findings

Nonlocality distillation achieves higher CHSH values with few copies.

Entanglement distillation guarantees Bell state generation with many copies.

Nonlocality distillation demonstrates superior resource efficiency.

Abstract

Given the goal of maximizing CHSH violation, we compare the optimal strategies of entanglement and nonlocality distillation. In the limit of the number of copies of the shared state, entanglement distillation is guaranteed to work by generating a Bell state. For a small number of copies of the state, we show that nonlocality distillation can achieve a higher CHSH value, even though optimal entanglement distillation requires communication. Nonlocality distillation not only outperforms entanglement distillation but also demonstrates superior resource efficiency across multiple metrics for quantum resource estimation.