Tunable couplings between location-insensitive emitters mediated by an epsilon-near-zero plasmonic waveguide

Area of Science:

• Quantum optics
• Condensed matter physics
• Nanotechnology

Background:

• Epsilon-near-zero (ENZ) materials offer unique electromagnetic properties.
• Graphene's tunable electronic properties are crucial for advanced devices.
• Controlling quantum coupling is essential for building quantum computers.

Purpose of the Study:

• To demonstrate efficient tuning of quantum emitter coupling in an ENZ waveguide.
• To realize a tunable two-qubit quantum phase gate.
• To explore entanglement generation in ENZ waveguides.

Main Methods:

• Utilizing an epsilon-near-zero (ENZ) waveguide coated with multilayer graphene.
• Operating at the cutoff frequency for tunable quantum phase gates.
• Tuning Fermi level of graphene to control coherent coupling.

Main Results:

• Achieved efficient tuning of incoherent and coherent coupling between emitters.
• Realized a tunable two-qubit quantum phase gate at the ENZ cutoff frequency.
• Demonstrated near-ideal bipartite and multipartite entanglement due to ENZ properties.
• Showcased tunable coherent coupling and energy transfer via graphene's Fermi level.

Conclusions:

• The ENZ waveguide platform with graphene provides efficient electro-optical tunability for quantum devices.
• This system enables enhanced control over quantum entanglement and gate operations.
• The findings pave the way for novel quantum information processing technologies.