Resonance energy transfer and quantum entanglement mediated by epsilon-near-zero and other plasmonic waveguide systems

Abstract

The entanglement and resonance energy transfer between two-level quantum emitters are typically limited to sub-wavelength distances due to the inherently short-range nature of the dipole-dipole interactions. Moreover, the entanglement of quantum systems is hard to preserve for a long time period due to decoherence and dephasing mainly caused by radiative and nonradiative losses. In this work, we outperform the aforementioned limitations by presenting efficient long-range inter-emitter entanglement and large enhancement of resonance energy transfer between two optical qubits mediated by epsilon-near-zero (ENZ) and other plasmonic waveguide types, such as V-shaped grooves and cylindrical nanorods. More importantly, we explicitly demonstrate that the ENZ waveguide resonant energy transfer and entanglement performance drastically outperforms the other waveguide systems. Only the excited ENZ mode has an infinite phase velocity combined with a strong and homogeneous electric field distribution, which leads to a giant energy transfer and efficient entanglement independent to the 2 emitters' separation distances and nanoscale positions in the ENZ nanowaveguide, an advantageous feature that can potentially accommodate multi-qubit entanglement. Moreover, the transient entanglement can be further improved and become almost independent of the detrimental decoherence effect when an optically active (gain) medium is embedded inside the ENZ waveguide. We also present that efficient steady-state entanglement can be achieved by using a coherent external pumping scheme. Finally, we report a practical way to detect the steady-state entanglement by computing the second-order correlation function. The presented findings stress the importance of plasmonic ENZ waveguides in the design of the envisioned onchip quantum communication and information processing plasmonic nanodevices. IntroductionOne of the main limitations of the current quantum photonic systems is the rapid loss of spatial and temporal coherence [1,2]. For instance, Förster resonance energy transfer [3], a well-known dipole-dipole interaction between quantum emitters important to light sources, biomedical imaging, and photovoltaic applications, is limited to subwavelength ranges [4,5]. In addition, quantum entanglement [6], which is significant for a variety of emerging applications in quantum communication and computing [7], usually takes place at extremely short distances and for very short time periods, due to the decoherence associated with unavoidable coupling between the system and the surrounding environment [8].During the last years, considerable research efforts have been dedicated to significantly improve coherence based on the emerging field of quantum plasmonic metamaterials [9,10]. These artificially engineered nanostructures can serve as a novel platform to trigger, harness, and enhance coherent light-matter interactions at the nanoscale [9,11]. For instance, long-range

Plasmon–Exciton Interactions: Spontaneous Emission and Strong Coupling

“…Simulation results show that large energy transfer rate between donor and acceptor can be obtained by coupling to wedge waveguide and V-groove channel waveguide, [200] and the energy transfer rate can be further improved by coupling the emitters to an epsilon-near-zero plasmonic waveguide. [201] For conjugated or randomly distributed donor-acceptor pairs, metal nanostructure in their vicinity can also influence the Förster type energy transfer. The energy transfer rate, efficiency, and Förster radius can be modified because of the coupling of the fluorophores with SPs.…”

“…[222,223] Theoretical studies have shown the quantum entanglement of two QEs mediated by plasmonic NPs and nanowaveguides. [201,[224][225][226][227][228][229]…”

Entangled light–matter interactions and spectroscopy

“…By altering the coupled polarization non-locally, the plasmonic device could in principle operate from perfect absorption to full transmission. The general idea of manipulating the material's functions non-locally via entanglement could lead to multifunctional integrated devices such as quantum logic gates, but also has fundamental advantages in processes like resonant energy transfer 104,123 .…”

Optimally Sharp Energy Filtering of Quantum Particles via Homogeneous Planar Inclusions

“…This study reports numerous highly selective setups that deploy actual quantum matter and thus provides the interested experimentalists with additional degrees of freedom in fabrication of sharp energy filters for quantum particles and their respective matter waves. This primitive library of optimal setups performing such a ubiquitous operation at each selected energy level can be also useful in integrated systems design with state-of-the-art quantum engineering applications of a huge range spanning from attosecond time resolution 36 and all-optical particle acceleration 37 to optimal field detection 38 and quantum signal processing 39,40 .…”