Noise robustness of the nonlocality of entangled quantum states.

Research paper by Mafalda L ML Almeida, Stefano S Pironio, Jonathan J Barrett, Géza G Tóth, Antonio A Acín

Indexed on: 07 Aug '07Published on: 07 Aug '07Published in: Physical review letters


We study the nonlocal properties of states resulting from the mixture of an arbitrary entangled state rho of two d-dimensional systems and completely depolarized noise, with respective weights p and 1-p. We first construct a local model for the case in which rho is maximally entangled and p at or below a certain bound. We then extend the model to arbitrary rho. Our results provide bounds on the resistance to noise of the nonlocal correlations of entangled states. For projective measurements, the critical value of the noise parameter p for which the state becomes local is at least asymptotically log(d) larger than the critical value for separability.