Fast generation of Schrödinger cat states using a Kerr-tunable superconducting resonator

Area of Science:

• Quantum physics
• Superconducting circuits
• Quantum information science

Background:

• Schrödinger cat states, quantum superpositions of distinct classical states, are vital for quantum communication, metrology, and computation.
• Existing methods for generating cat states in 3D cavities or with strong drives face scalability and controllability issues.

Purpose of the Study:

• To present a novel strategy for generating and preserving cat states in a scalable, chip-based superconducting circuit.
• To overcome the limitations of traditional methods for cat state generation.

Main Methods:

• Utilized a coplanar superconducting circuit.
• Employed fast modulation of Kerr nonlinearity to generate cat states.
• Leveraged a Kerr-free work point for passive preservation of cat states.

Main Results:

• Successfully generated a 2-component cat state in a chip-based device.
• Achieved a fidelity of 89.1% for the cat state.
• Demonstrated passive preservation of cat states due to vanishing Kerr effect.

Conclusions:

• The proposed scheme offers a viable route for constructing chip-based bosonic quantum processors.
• This method enhances the scalability and controllability of cat state generation.
• The results pave the way for practical applications in quantum information processing.