Simulation of two spin-$s$ singlet correlations for all $s$ involving spin measurements

TL;DR

This paper presents a classical protocol that exactly simulates quantum correlations of spin-$s$ singlet states for all integer and half-integer spins using only spin measurements, with communication cost depending on the spin value.

Contribution

The authors generalize previous results by providing a classical simulation protocol for all spin-$s$ singlet states, extending beyond specific spin sequences.

Findings

Classical simulation protocol for all spin-$s$ singlet correlations

Communication cost is logarithmic in the spin value

Exact simulation of quantum correlations for spin measurements

Abstract

In a recent paper [A. Ahanj et al., quant-ph/0603053], we gave a classical protocol to simulate quantum correlations corresponding to the spin $s$ singlet state for the infinite sequence of spins satisfying $2s+1 = 2^{n}$. In the present paper, we have generalized this result by giving a classical protocol to exactly simulate quantum correlations implied by the spin-$s$ singlet state corresponding to all integer as well as half-integer spin values $s$. The class of measurements we consider here are only those corresponding to spin observables, as has been done in the above-mentioned paper. The required amount of communication is found to be $\lceil {\rm log}_{2} (s + 1) \rceil$ in the worst case scenario, where $\lceil x \rceil$ is the least integer greater than or equal to $x$.