Know What's Happening in Quantum

Entanglement Via Classical Mediators Achieved Using Hybrid Van Hove Theory

Scientists Ulbricht, Bermúdez Manjarres and Reginatto show that two quantum spins become entangled when their interaction is mediated solely by a classical harmonic oscillator, using a hybrid van Hove theory. The framework combines Schrödinger operators for quantum parts with van Hove operators for classical observables, preserving both Poisson and commutator structures. Analytical calculations of the spin density matrix reveal non‑zero concurrence, directly challenging traditional no‑go theorems that forbid entanglement via classical channels. The work suggests that entanglement alone cannot definitively prove the quantum nature of a mediator such as gravity.