Pulse-based optimization of quantum many-body states with Rydberg atoms in optical tweezer arrays

TL;DR

This paper introduces a pulse-based variational quantum eigensolver for Rydberg atom arrays, demonstrating accurate ground state preparation of quantum spin models and proposing a hybrid analog-digital approach for efficient measurements.

Contribution

It presents a novel pulse-level VQE algorithm for Rydberg atoms and a hybrid scheme combining analog pulses with digital gates for improved efficiency.

Findings

Accurately prepared ground states of 1D antiferromagnetic Heisenberg and Ising models.

Demonstrated the algorithm's effectiveness on systems of up to ten qubits.

Validated a hybrid analog-digital quantum approach for measuring many-body Hamiltonians.

Abstract

We explore a pulse-based variational quantum eigensolver (VQE) algorithm for Rydberg atoms in optical tweezer arrays and evaluate its performance on prototypical quantum spin models. We numerically demonstrate that the ground states of the one-dimensional antiferromagnetic Heisenberg model and the mixed-field Ising model can be accurately prepared using an adaptive update algorithm that randomly segments pulse sequences, for systems of up to ten qubits. Furthermore, we propose and validate a hybrid scheme that integrates this pulse-level analog quantum algorithm with a variational quantum gate approach, where digital quantum gates are approximated by optimized analog pulses. This enables efficient measurement of the cost function for target many-body Hamiltonians.