Impact and mitigation of Hamiltonian characterization errors in digital-analog quantum computation

TL;DR

This paper analyzes the impact of Hamiltonian characterization errors in digital-analog quantum computing and proposes mitigation strategies to improve scalability and accuracy.

Contribution

It provides bounds on Hamiltonian errors and introduces a mitigation protocol resembling dynamical decoupling for digital-analog quantum systems.

Findings

Bound on maximum separation between target and implemented Hamiltonians

Upper bound on deviation of observable measurements due to errors

Mitigation protocol reduces calibration errors effectively

Abstract

Digital-analog is a universal quantum computing paradigm which employs the natural entangling Hamiltonian of the system and single-qubit gates as resources. Here, we study the stability of these protocols against Hamiltonian characterization errors. For this, we bound the maximum separation between the target and the implemented Hamiltonians. Additionally, we obtain an upper bound for the deviation in the expected value of an observable. We further propose a protocol for mitigating calibration errors which resembles dynamical-decoupling techniques. These results open the possibility of scaling digital-analog to intermediate and large scale systems while having an estimation on the errors committed.