Generating Multipartite Spin States with Fermionic Atoms in a Driven Optical Lattice.

Area of Science:

• Quantum Information Science
• Atomic Physics
• Condensed Matter Physics

Background:

• Generating multi-particle entanglement is crucial for quantum technologies.
• Ultracold atoms in optical lattices offer a controllable platform for quantum simulations and computing.
• Standard entanglement protocols often face challenges with scalability and robustness.

Purpose of the Study:

• To propose a novel protocol for generating generalized Greenberger-Horne-Zeilinger (GHZ) states.
• To utilize ultracold fermions in 3D optical lattices or optical tweezer arrays for this purpose.
• To enable applications in quantum-enhanced metrology.

Main Methods:

• Employing laser driving, on-site interactions, and trapping potentials.
• Enforcing energetic spin- and position-dependent constraints on atomic motion.
• A stepwise protocol transforming local superpositions into GHZ states one site at a time.

Main Results:

• The protocol does not require site-resolved drives or spin-dependent potentials.
• Demonstrated robustness against slow global laser phase drift.
• The method naturally integrates with harmonic trap potentials in optical lattices.
• An improved protocol is discussed for compensating loadout imperfections.

Conclusions:

• The proposed protocol offers a viable route to generate generalized GHZ states with ultracold fermions.
• This method enhances the feasibility of quantum-enhanced metrology in 3D optical lattice clocks.
• The work paves the way for pushing sensor sensitivity beyond the standard quantum limit.