Probing the Kitaev honeycomb model on a neutral-atom quantum computer

TL;DR

This paper demonstrates a digital quantum simulation of a 2D fermionic system using a neutral-atom quantum computer, enabling exploration of topological phases, fermion statistics, and complex interactions relevant to materials and physics.

Contribution

It introduces a novel quantum simulation architecture for 2D fermionic models using atom arrays, including state preparation, evolution, and error detection techniques.

Findings

Preparation of topological states in the Kitaev model

Verification of non-Abelian spin liquid phase via Chern number

Simulation of Fermi-Hubbard model dynamics

Abstract

Quantum simulations of many-body systems are among the most promising applications of quantum computers. In particular, models based on strongly-correlated fermions are central to our understanding of quantum chemistry and materials problems, and can lead to exotic, topological phases of matter. However, due to the non-local nature of fermions, such models are challenging to simulate with qubit devices. Here we realize a digital quantum simulation architecture for two-dimensional fermionic systems based on reconfigurable atom arrays. We utilize a fermion-to-qubit mapping based on Kitaev's model on a honeycomb lattice, in which fermionic statistics are encoded using long-range entangled states. We prepare these states efficiently using measurement and feedforward, realize subsequent fermionic evolution through Floquet engineering with tunable entangling gates interspersed with atom rearrangement, and improve results with built-in error detection. Leveraging this fermion description of the Kitaev spin model, we efficiently prepare topological states across its complex phase diagram and verify the non-Abelian spin liquid phase by evaluating an odd Chern number. We further explore this two-dimensional fermion system by realizing tunable dynamics and directly probing fermion exchange statistics. Finally, we simulate strong interactions and study dynamics of the Fermi-Hubbard model on a square lattice. These results pave the way for digital quantum simulations of complex fermionic systems for materials science, chemistry, and high-energy physics.