.png){kind=icon}
.png){kind=icon}
Return
Entanglement source and quantum memory analysis for
.png){kind=icon}
OA
AI
DOI：10.1103/PhysRevApplied.22.044014.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
High-rate, high-fidelity entanglement distribution is essential to the creation of a quantum internet, but recent achievements in fiber (248 km at a 9-s-1 rate) and satellite-based (1200 km at a 1.1-s-1 rate) entanglement distribution fall far short of what is needed. Chen et al. [Phys. Rev. Appl. 19, 054209 (2023)] proposed a means for dramatically increasing entanglement-distribution rates via a scheme they called zero-added-loss multiplexing (ZALM). ZALM's quantum transmitter employs a pair of Sagnac-configured spontaneous parametric down-converters (SPDCs), channelization via dense wavelength-division multiplexing (DWDM) filtering, and partial Bell-state measurements (BSMs) to realize a heralded source of frequency-multiplexed polarization-entangled biphotons. Each biphoton is transmitted to Alice and Bob along with a classical message identifying its frequency channel and whether a Ili- singlet or a Ili+ triplet was heralded. Alice's and Bob's quantum receivers then use DWDM filtering and temporal-mode conversion to interface their received biphotons to intracavity color-center quantum memories. This paper delves deeply into ZALM's SPDCs, partial BSMs, and Duan-Kimble loading of Alice's and Bob's quantum memories. Its principal results-the density operators for the SPDC sources and the quantum memories-allow heralding probability, heralding efficiency, and fidelity to be evaluated for both the polarization-entangled biphotons and the loaded quantum memories, thus enabling exploration of the parameter space for optimizing ZALM's performance. Even without a comprehensive optimization analysis, the paper's examples already demonstrate two critical features of the ZALM architecture: (1) the necessity of achieving a near-separable channelized biphoton wave function to ensure that the biphoton sent to Alice and Bob is of high purity; and (2) the premium placed on Alice's and Bob's temporal-mode converters enabling narrowband push-pull memory loading to ensure that the arriving biphoton's state is faithfully transferred to the intracavity color centers.
Keywords:
EFFICIENT GENERATION
PHOTONS
STATE