Quantum Feedback-Enhanced Discord in V-Shaped Plasmonic Waveguides

Abstract

This theoretical and numerical investigation explores the enhancement and preservation of quantum discord in quantum systems coupled through V-shaped plasmonic waveguides (V-PW) using advanced quantum feedback control techniques. We demonstrate that properly engineered quantum feedback can significantly improve quantum discord preservation, particularly in Werner states where we observe enhancements from zero to 0.38 under optimal conditions. The mechanism involves a sophisticated confinement of the quantum state within protected subspaces that are resilient against environmental decoherence. Through detailed theoretical modeling and extensive numerical simulations, we identified the key parameters governing this enhancement process, including waveguide geometry, emitter positioning, and feedback timing. Our results reveal three distinct quantum discord decay temporal regimes and establish optimal operating conditions for maximal quantum correlation preservation. The findings provide fundamental insights into quantum correlation dynamics in nanophotonic systems and practical guidelines for experimental implementations in quantum information processing applications, with particular relevance to room-temperature quantum technologies.