Classical communication cost of quantum steering

TL;DR

This paper investigates the classical communication required to simulate quantum steering, revealing that infinite communication is needed for exact simulation of pure entangled states and highlighting fundamental differences from Bell nonlocality.

Contribution

It establishes the minimum communication cost for simulating quantum steering and compares it to Bell nonlocality, providing new insights into the strength of quantum correlations.

Findings

Infinite communication needed for exact simulation of pure entangled states

Differences between steering and Bell nonlocality

Insights into the strength of quantum correlations

Abstract

Quantum steering is observed when performing appropriate local measurements on an entangled state. Here we discuss the possibility of simulating classically this effect, using classical communication instead of entanglement. We show that infinite communication is necessary for exactly simulating steering for any pure entangled state, as well as for a class of mixed entangled states. Moreover, we discuss the communication cost of steering for general entangled states, as well as approximate simulation. Our findings reveal striking differences between Bell nonlocality and steering, and provide a natural way of measuring the strength of the latter.