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Quantum 2.0 Conference and Exhibition

Effective Density Matrices in Entangled Photon Detection

Taman Truong, Christian Arenz, Joseph M. Lukens

Published Jan 1, 2025• 0 citations
Publisher

Abstract

We develop a practical, mathematical model for the effective two-photon density matrix produced by a parametric source of entangled photon pairs under two and four photon-number-resolving and threshold detectors.
DOI
10.1364/quantum.2025.qw4b.3

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Quantum entanglement is an essential resource for quantum networks. However, the generation of entanglement between physical devices at remote network nodes is a challenging task towards practical implementation of quantum networks. In this work, we use the open-source Simulator of QUantum Network Communication (SeQUeNCe), developed by our team, to simulate entanglement generation between two atomic frequency comb (AFC) absorptive quantum memories to be deployed on the Argonne-Chicago quantum network. We realize the representation of photonic quantum states within truncated Fock spaces in SeQUeNCe and build models for a spontaneous parametric down-conversion (SPDC) source, AFC absorptive quantum memories, and measurement devices with non-number-resolving photon detectors. Based on these developments, we observe varying fidelity with SPDC source mean photon number, and varying entanglement generation rate with both mean photon number and memory mode number. We also simulate tomographic reconstruction of the effective density matrix for the bipartite photonic states retrieved from quantum memories. Our work extends the usability of the SeQUeNCe simulator with new hardware modules and Fock state representation that will improve the simulation of near term quantum network hardware and protocols.
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