Tree-Codes Enable Top-to-Bottom Fast Quantum Encoding/Decoding

Researchers have devised a new method for generating entangled photonic states that significantly improves the feasibility of long-distance quantum communication. Unlike previous proposals, the technique enables “top-to-bottom fast encoding and decoding,” reducing losses caused by delays and photon reordering at quantum repeater stations. At the heart of this advance is a single quantum emitter equipped with a static feedback mechanism, allowing researchers to engineer entangling gates between a fed-back qubit and multiple emitted qubits in parallel. Analyzing error-correction decoding graphs also revealed that introducing asymmetries into tree-code structure can improve performance while simultaneously reducing code size; these asymmetries mimic…