Transient and steady-state entanglement mediated by three-dimensional plasmonic waveguides

Area of Science:

• Quantum physics
• Nanophotonics
• Materials science

Background:

• Surface plasmons enable light-matter interactions at the nanoscale.
• Plasmonic waveguides offer novel architectures for quantum information processing.
• Understanding qubit-environment interactions is crucial for quantum technologies.

Purpose of the Study:

• To investigate entanglement generation between two qubits mediated by surface plasmons.
• To analyze the impact of waveguide geometry and length on qubit entanglement.
• To explore methods for enhancing qubit-waveguide coupling and entanglement.

Main Methods:

• Utilized a quantum master equation formalism to model qubit dynamics.
• Calculated waveguide Green functions using finite-difference time-domain (FDTD) solutions of Maxwell's equations.
• Investigated both infinite and finite-length plasmonic waveguides, including nanowire and V-shaped channel designs.

Main Results:

• Finite-length effects were found to critically enhance qubit entanglement.
• Resonant-length plasmonic waveguides demonstrated superior entanglement compared to infinite ones.
• Coupling slots improved entanglement by strengthening qubit-waveguide interactions.

Conclusions:

• Plasmonic waveguides, particularly finite-length designs, are promising for robust quantum entanglement.
• Optimizing waveguide geometry and coupling mechanisms can significantly boost quantum information processing capabilities.
• The employed formalism is adaptable for diverse plasmonic waveguide systems.