Heralding Multiple Photonic Pulsed Bell Pairs via Frequency-Resolved Entanglement Swapping

Abstract

Entanglement is a unique property of quantum systems and an essential resource for many quantum technologies. The ability to transfer or swap entanglement between systems is an important protocol in quantum information science. Entanglement between photons forms the basis of distributed quantum networks and the demonstration of photonic entanglement swapping is essential for their realization. Here an experiment demonstrating entanglement swapping from two independent multimode time-frequency entangled sources is presented, resulting in multiple heralded temporal-mode Bell states. Entanglement in the heralded states is verified by measuring conditional anti-correlated joint spectra as well as quantum beating in two-photon interference. Our proof-of-concept experiment is able to distinguish up to five orthogonal Bell pairs within the same setup, limited in principle only by the entanglement of the sources.

Delayed-choice quantum erasure with nonlocal temporal double-slit interference

“…To tackle this issue, we use a narrow band spectral filter (by narrowing the width of the tunable slit in our experiment) to erase the which-time information. This method has been used in the frequency-resolved entanglement swapping and multi-photon interference such that the temporal distinguishability from independent entanglement sources can be erased by using fiber Bragg grating to achieve ultranarrow frequency bandwidth, namely ultralong coherence time [58][59][60][61][62].…”

Entanglement swapping under global noise environment

“…Now we consider the input states of qubit pairs with numbers (1, 2) and (3,4) given by: where θ ∈ (0, π). As a result, the density matrices for the qubit pairs with numbers (1, 2) and (3, 4) take individually the forms of ρ 12 = |φ⟩ 12 ⟨φ|, ρ 34 = |φ⟩ 34 ⟨φ|.…”

“…Entanglement is a unique property of quantum systems, and an essential resource for many quantum technologies [1,2], such as quantum teleportation, quantum cryptography protocols, super-dense coding, etc. The ability to transfer or swap entanglement between systems is an important protocol in quantum information science [3]. Entanglement swapping [4], the process of entangling two particles without coupling them * Author to whom any correspondence should be addressed.…”

“…in any way, is one of the most striking manifestations of the quantum-mechanical nonlocal characteristic [5]. Besides being of fundamental interest, this process has applications [3,[6][7][8][9][10][11][12][13][14] in complex entanglement manipulation and quantum communication.…”

Simulation of a polarization-transverse momentum hyperentangled photon source

“…It is used in quantum teleportation, 1 , 2 quantum dense coding, 3 , 4 quantum secret sharing, 5 , 6 quantum key distribution, 7 , 8 quantum secured direct communication, 9 – 11 and quantum entanglement swapping 12 – 14 Entangled photon pairs can simultaneously possess more than one degree of freedom (DOF). This is known as hyperentanglement.…”