When the photon interacts with the quantum reminiscence, it turns into entangled with the reminiscence – which means that measurements carried out on both the photon or the reminiscence would supply data on (and thus modify) the state of the opposite.
Nonetheless, as an alternative of measuring the photon (and thus extracting the data), the photon undergoes quantum frequency conversion from seen frequency (the place the quantum reminiscence operates) to telecom frequency (the place losses in optical fiber are minimized). The (now telecom-frequency) photon then makes a spherical journey by an underground fiber community earlier than returning to Harvard, the place it’s transformed again to seen frequency.
This journey achieved, the photon is bounced off a unique quantum reminiscence in a unique lab, thus transferring the entanglement from the photon onto this second reminiscence. Lastly, the photon, having bounced off the second reminiscence, is then routed to a detector which notes the presence of a photon, however doesn’t reveal any of the underlying quantum data contained within the mild.It entangled with the reminiscence — which means that measuring both the photon or the reminiscence modifies the state of the opposite. The photon then converts from a visual frequency to a telecom frequency, which then bounces to a unique lab, thus finishing the journey.