Full‐Stack Physics‐Level Model of Cascaded Entanglement Links

ABSTRACT While the last few decades have seen a proliferation of experimental demonstrations of entanglement sources, practicality of deployment has been a secondary concern. Recently, the ZALM source was introduced as a well‐engineered functional device easily integrated within a complete networking system. It addresses numerous concerns, which make typical academic demonstrations less practical: reliable heralding signals, multiplexing across multiple dimensions, and efficient use of input power. We present a stack of tools for modeling mode‐by‐mode a ZALM source under realistic conditions, in isolation or as a part of a complete network testbed. Our modeling formalism builds upon a hybrid Gaussian and non‐Gaussian representation, providing a flexible tradeoff between performance and accuracy, while also greatly simplifying the exact calculation of otherwise expensive scalar figures of merit. This toolkit, implemented in the Python package called “genqo,” is integrated within the QuantumSavory full‐stack simulator and the QuantumSymbolics computer algebra system. We use this software stack to demonstrate a number of complete networking protocols built upon the ZALM source.