Minisymposium Presentation
Comparing Performance of Variational Quantum Algorithm Simulations on HPC Systems
Presenter
Luigi Iapichino holds the position of Lead of the User Enablement and Applications group, in the Quantum Computing and Technologies department at LRZ, and in this role he is shaping LRZ's service portfolio and training program in the field of QC. He is co-founder of the Bavarian Quantum Computing eXchange (BQCX). Among his research interests are quantum computing simulations on high-end HPC systems and HPCQC applications. He completed in 2005 his PhD in physics at the Technical University of Munich, working at the Max Planck Institute for Astrophysics. At LRZ he was team lead of the Application Lab for Astro and Plasma Physics (AstroLab).
Description
The variational quantum algorithms have a special importance in the research on quantum computing applications, for their applicability on current noisy intermediate-scale quantum (NISQ) devices. The main building blocks of these algorithms (e.g., the definition of the Hamiltonian and of the ansatz, the parameter optimization) define a relatively large parameter space, making the comparison of results and performance between different software simulators cumbersome and prone to errors. In this work, we employ a generic description of the problem, in terms of both Hamiltonian and ansatz to port a problem definition consistently among different simulators. Three use cases of relevance for current quantum hardware (ground state calculation for H_2 molecule, MaxCut, Travelling Salesman Problem) have been run on a set of HPC systems (shared-memory, multi-node, GPU-accelerated). The results show that, for some of the most used QC simulation packages, simple variational workloads present performance and scaling challenges. The presented parser allows a fair comparison of the performance while ensuring that problem definition and physical results stay consistent.