Finite Nonsignalling Resources Suffice to Simulate Entangled Qubits

arXiv:2610.32319v1 Announce Type: new Abstract: A longstanding question in Bell nonlocality is whether finite-alphabet nonsignalling resources can reproduce the continuum of measurement correlations of partially entangled qubits. Here we resolve this problem by showing that every fixed pure two-qubit state admits an exact simulation of all local projective-measurement statistics using shared randomness and finitely many Popescu-Rohrlich (PR) boxes, without communication or postselection. The boxes operate in parallel, with a worst-case bound independent of the measurement settings: at most $128\cot^4\theta$ calls for the Schmidt state $\cos\theta|00\rangle+\sin\theta|11\rangle$, $0<\theta<\pi/4$.