Electromagnetically Induced Transparency in Circuit Quantum Electrodynamics with Nested Polariton States

Area of Science:

• Quantum Information Science
• Quantum Computing
• Quantum Communication

Background:

• Quantum networks require reliable quantum state storage and manipulation at nodes.
• Superconducting circuits offer a promising platform for building quantum network components.

Purpose of the Study:

• To demonstrate a functional quantum network node capable of conditional quantum state manipulation.
• To utilize quantum interference for controlled signal transmission.

Main Methods:

• Employing electromagnetically induced transparency (EIT) in a transmon qubit coupled to a superconducting resonator.
• Preparing a Lambda-type three-level system of polariton states using microwave bias.
• Inputting interchangeable microwave probe and control tones to modulate signal transmission.

Main Results:

• Achieved conditional transmission of a probe tone based on the presence of a control tone.
• Demonstrated up to 99.73% transmission extinction, indicating high on/off ratios.
• Inferred high dark state preparation fidelities (>99.39%) and negative group velocities (-0.52±0.09 km/s).

Conclusions:

• The demonstrated EIT scheme provides a robust method for quantum state control in network nodes.
• This work is a significant step towards building functional quantum networks.
• The use of all dipole-allowed transitions simplifies the implementation and enhances scalability.