Experimentally simulating the dynamics of quantum light and matter at deep-strong coupling

Area of Science:

• Quantum physics
• Quantum optics
• Solid-state physics

Background:

• The quantum Rabi model is fundamental to understanding light-matter interactions.
• Ultrastrong and deep-strong coupling regimes exhibit phenomena like quantum phase transitions and entanglement.
• Experimentally demonstrating dynamics in these regimes is challenging, with existing methods limited to spectroscopy.

Purpose of the Study:

• To achieve accurate digital quantum simulation of deep-strong coupling dynamics.
• To explore quantum phase transitions and entanglement in extreme coupling regimes.
• To advance solid-state digital quantum simulation capabilities.

Main Methods:

• Utilized a circuit quantum electrodynamics chip with a resonator and transmon qubit.
• Employed up to 90 second-order Trotter steps for digital quantum simulation.
• Probed both subsystems within a combined Hilbert space dimension of approximately 80.

Main Results:

• Successfully simulated deep-strong coupling dynamics.
• Observed characteristic Schrödinger-cat-like entanglement.
• Demonstrated significant photon build-up.

Conclusions:

• The study represents a significant step in solid-state digital quantum simulation.
• The developed approach enables the exploration of extreme coupling regimes and quantum phase transitions.
• This work paves the way for simulating more complex quantum models like the Dicke model.