Loophole-free Bell test with one atom and less than one photon on average
Loophole-free Bell test with one atom and less than one photon on average
We consider the entanglement between two internal states of a single atom and two photon number states describing either the vacuum or a single photon and thus containing, on average, less than one photon. We show that this intriguing entanglement can be characterized through substantial violations of a Bell inequality …