Ancillary entangling Floquet kicks for accelerating quantum algorithms

TL;DR

This paper introduces ancillary entangling Floquet kicks to accelerate quantum algorithms, significantly improving solution times and accuracy in quantum simulations of Ising models and molecular systems.

Contribution

It presents a novel method using ancillary entangling Floquet kicks to enhance quantum simulation efficiency and accuracy, overcoming traditional adiabatic annealing limitations.

Findings

100% reduction in solution time for tested models

Higher accuracy achieved through the proposed method

Validated by numerical simulation and Hamiltonian theory

Abstract

Quantum simulation with adiabatic annealing can provide insight into difficult problems that are impossible to study with classical computers. However, it deteriorates when the systems scale up due to the shrinkage of the excitation gap and thus places an annealing rate bottleneck for high success probability. Here, we accelerate quantum simulation using digital multi-qubit gates that entangle primary system qubits with the ancillary qubits. The practical benefits originate from tuning the ancillary gauge degrees of freedom to enhance the quantum algorithm's original functionality in the system subspace. For simple but nontrivial short-ranged, infinite long-ranged transverse-field Ising models, and the hydrogen molecule model after qubit encoding, we show improvement in the time to solution by one hundred percent but with higher accuracy through exact state-vector numerical simulation in a digital-analog setting. The findings are further supported by time-averaged Hamiltonian theory.