Testing nonlocality over 12.4 km of underground fiber with universal time-bin qubit analyzers

Abstract

We experimentally demonstrate that the nonlocal nature of time-bin entangled photonic qubits persists when one or two qubits of the pair are converted to polarization qubits. This is possible by implementing a novel Universal Time-Bin Qubit Analyzer (UTBA), which, for the first time, allows analyzing time-bin qubits in any basis. We reveal the nonlocal nature of the emitted light by violating the Clauser-Horne-Shimony-Holt inequality with measurement bases exploring all the dimensions of the Bloch sphere. Moreover, we conducted experiments where one qubit is transmitted over a 12.4 km underground fiber link and demonstrate the suitability of our scheme for use in a real-world setting. The resulting entanglement can also be interpreted as hybrid entanglement between different types of degrees of freedom of two physical systems, which could prove useful in large scale, heterogeneous quantum networks. This work opens new possibilities for testing nonlocality and for implementing new quantum communication protocols with time-bin entanglement.

6 pages, 5 figures

References in corpus (11)

• The Quantum Internet
• Free-Space distribution of entanglement and single photons over 144 km
• An experimental test of non-local realism
• Realization and characterization of a 2-photon 4-qubit linear cluster state
• Testing quantum correlations versus single-particle properties within Leggett's model and beyond
• Experimental Falsification of Leggett's Non-Local Variable Model
• Proof-of-Concept of Real-World Quantum Key Distribution with Quantum Frames
• Experimental violation of a Bell inequality with two different degrees of freedom of entangled particle pairs
• Hybrid photonic entanglement: Realization, characterization and applications
• Fair Loss-Tolerant Quantum Coin Flipping
• Control of quantum interference in the quantum eraser

Cited by in corpus (11)

• Quantum Storage of Photonic Entanglement in a Crystal
• Real-world two-photon interference and proof-of-principle quantum key distribution immune to detector attacks
• Spin-orbit hybrid entanglement of photons and quantum contextuality
• Flipping quantum coins
• Efficient single-spatial-mode periodically-poled KTiOPO_4 waveguide source for high-dimensional entanglement-based quantum key distribution
• Single pairs of time-bin entangled photons
• Time-bin to Polarization Conversion of Ultrafast Photonic Qubits
• Cross-phase modulation of a probe stored in a waveguide for non-destructive detection of photonic qubits
• Two-step frequency conversion for connecting distant quantum memories by transmission through an optical fiber
• Interference and complementarity for two-photon hybrid entangled states
• Photonic quantum information with time-bins: Principles and applications