# Activation of nonlocality in bound entanglement

## TL;DR

This paper demonstrates that bound entangled states can exhibit hidden nonlocality through local filtering, revealing activation of nonlocality in states previously thought to be local under general measurements.

## Contribution

It provides the first example of activation of nonlocality in bound entanglement, showing that such states can admit local models for general measurements but reveal nonlocality after filtering.

## Key findings

- Bound entangled states can have local models for general measurements.
- Local filters can activate nonlocality in bound entangled states.
- Hidden nonlocality does not necessarily imply entanglement distillability.

## Abstract

We discuss the relation between entanglement and nonlocality in the hidden nonlocality scenario. Hidden nonlocality signifies nonlocality that can be activated by applying local filters to a particular state that admits a local hidden-variable model in the Bell scenario. We present a fully-biseparable three-qubit bound entangled state with a local model for the most general (non-sequential) measurements. This proves for the first time that bound entangled states can admit a local model for general measurements. We furthermore show that the local model breaks down when suitable local filters are applied. Our results demonstrate the first example of activation of nonlocality in bound entanglement. Hence, we show that genuine hidden nonlocality does not imply entanglement distillability.