Quantum Rabi dynamics of trapped atoms far in the deep strong coupling regime

Area of Science:

• Quantum Physics
• Quantum Optics
• Atomic Physics

Background:

• The quantum Rabi model describes the interaction between a two-level system and an electromagnetic field, a fundamental concept in quantum physics.
• The deep strong coupling regime, where coupling strength significantly exceeds field mode frequency, allows for excitation creation from the vacuum.

Purpose of the Study:

• To experimentally realize a periodic variant of the quantum Rabi model.
• To explore the deep strong coupling regime using cold atoms in optical potentials.
• To investigate the dynamics of quantum systems in unexplored parameter regimes.

Main Methods:

• Encoding a two-level system within the Bloch band structure of cold rubidium atoms.
• Utilizing optical potentials to create and control the atomic system.
• Achieving a Rabi coupling strength 6.5 times the field mode frequency.

Main Results:

• Demonstration of a Rabi coupling strength far into the deep strong coupling regime.
• Observation of a subcycle timescale increase in bosonic field mode excitations.
• Revealing freezing of dynamics for small frequency splittings and revival for larger splittings in measurements.

Conclusions:

• The study successfully demonstrates a novel approach to the quantum Rabi model in the deep strong coupling regime.
• The observed phenomena provide insights into quantum dynamics under extreme coupling conditions.
• This work paves the way for quantum-engineering applications in previously inaccessible parameter ranges.