Emergence of multi-body interactions in a fermionic lattice clock

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Simulation
• Condensed Matter Physics

Background:

• Alkaline-earth atoms possess metastable clock states ideal for atomic clocks, quantum information, and simulation.
• Few-particle systems are crucial for observing emergent many-body phenomena.
• Multi-body interactions are key to exotic quantum matter but underexplored in ultracold fermions.

Purpose of the Study:

• To investigate emergent multi-body interactions in ultracold fermionic strontium atoms.
• To observe and characterize both elastic and inelastic multi-body effects.
• To explore the potential of few-body systems for quantum magnetism and Kondo effect studies.

Main Methods:

• Creation of isolated few-body systems using fermionic 87Sr atoms in a 3D optical lattice.
• High-resolution clock spectroscopy to measure frequency shifts with varying atom numbers (n=1-5).
• Measurement of clock state lifetimes on n-occupied lattice sites to study inelastic interactions.

Main Results:

• Direct observation of elastic multi-body interactions via nonlinear frequency shifts.
• Elucidation of emergent SU(N)-symmetric multi-body interactions unique to fermionic alkaline-earth atoms.
• Agreement between measured lifetimes and theoretical predictions, indicating universality in ultracold collisions.

Conclusions:

• Few-body systems in optical clocks provide a platform to study emergent multi-body interactions.
• The observed interactions are crucial for future quantum simulations of magnetism and the Kondo effect.
• This work demonstrates a novel approach to probe short-range few-body physics with high precision.