Three-qubit encoding in ytterbium-171 atoms for simulating 1+1D QCD

TL;DR

This paper introduces a method to encode three qubits within individual ytterbium-171 atoms, enabling efficient simulation of 1+1D quantum chromodynamics phenomena like vacuum oscillations and string breaking.

Contribution

The authors develop a novel three-qubit encoding scheme in ytterbium-171 atoms and demonstrate universal gate operations for simulating quantum chromodynamics in 1+1D.

Findings

Successfully encoded three qubits in a single atom

Demonstrated universal gate set and readout protocol

Simulated vacuum oscillations and string breaking with two atoms

Abstract

Simulating nuclear matter described by quantum chromodynamics using quantum computers is notoriously inefficient because of the assortment of quark degrees of freedom such as matter/antimatter, flavor, color, and spin. Here, we propose to address this resource efficiency challenge by encoding three qubits within individual ytterbium-171 atoms of a neutral atom quantum processor. The three qubits are encoded in three distinct sectors: an electronic "clock" transition, the spin-1/2 nucleus, and the lowest two motional states in one radial direction of the harmonic trapping potential. We develop a family of composite sideband pulses and demonstrate a universal gate set and readout protocol for this three-qubit system. We then apply it to single-flavor quantum chromodynamics in 1+1D axial gauge for which the three qubits directly represent the occupancy of quarks in the three colors. We show that two atoms are sufficient to simulate both vacuum persistence oscillations and string breaking. We consider resource requirements and connections to error detection/correction. Our work is a step towards resource-efficient digital simulation of nuclear matter and opens new opportunities for versatile qubit encoding in neutral atom quantum processors.