Loss-tolerant state engineering for quantum-enhanced metrology via the reverse Hong-Ou-Mandel effect.
Highly entangled quantum states, shared by remote parties, are vital for quantum communications and metrology. Particularly promising are the N00N states-entangled N-photon wavepackets delocalized between two different locations-which outperform coherent states in measurement sensitivity. However, these states are notoriously vulnerable to losses, making them difficult to both share them between remote locations and recombine in order to exploit interference effects. Here we address this challenge by utilizing the reverse Hong-Ou-Mandel effect to prepare a high-fidelity two-photon N00N state shared between two parties connected by a lossy optical medium. We measure the prepared state by two-mode homodyne tomography, thereby demonstrating that the enhanced phase sensitivity can be exploited without recombining the two parts of the N00N state. Finally, we demonstrate the application of our method to remotely prepare superpositions of coherent states, known as Schrödinger's cat states.
Russian Quantum Center, 100 Novaya Street, Skolkovo, Moscow 143025, Russia.|Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia.
Alexander E
0000-0003-2211-559X
AE
Ulanov
Russian Quantum Center, 100 Novaya Street, Skolkovo, Moscow 143025, Russia.|P.N. Lebedev Physics Institute, Leninskiy prospect 53, Moscow 119991, Russia.
Ilya A
IA
Fedorov
Russian Quantum Center, 100 Novaya Street, Skolkovo, Moscow 143025, Russia.
Demid
D
Sychev
Laboratoire Charles Fabry, Institut d'Optique Graduate School, CNRS, Université Paris-Saclay, Palaiseau 91127, France.
Philippe
P
Grangier
Russian Quantum Center, 100 Novaya Street, Skolkovo, Moscow 143025, Russia.|P.N. Lebedev Physics Institute, Leninskiy prospect 53, Moscow 119991, Russia.|Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
A I
AI
Lvovsky