International Business Machines Corporation
ENTANGLED MICROWAVE-PHOTON-PAIR GENERATOR

Abstract:

A quantum-mechanical photon-pair generator includes first, second, third, and fourth Josephson junctions electrically connected in a bridge circuit having first, second and third resonance eigenmodes, and a source of magnetic flux configured to provide, during operation, a magnetic flux through the bridge circuit to cause coupling between the first, second and third resonance eigenmodes when the third resonance eigenmode is excited. The photon-pair generator further includes first, second and third electromagnetic resonators having eigenmodes in resonance with the first, second and third resonance eigenmodes of the bridge circuit, respectively. The third frequency of the third resonance eigenmode is equal to a sum of a first frequency of the first resonance eigenmode plus a second frequency of the second resonance eigenmode such that, during operation, a photon having the third frequency is split into two quantum-mechanically entangled photons having the first and second frequencies, respectively.