Hybrid Quantum Classical Simulations

RWTH Publications (RWTH Aachen)

Abstract

We report on two major hybrid applications of quantum computing, namely, the quantum approximate optimisation algorithm (QAOA) and the variational quantum eigensolver (VQE). Both are hybrid quantum classical algorithms as they require incremental communication between a classical central processing unit and a quantum processing unit to solve a problem. We find that the QAOA scales much better to larger problems than random guessing, but requires significant computational resources. In contrast, a coarsely discretised version of quantum annealing called approximate quantum annealing (AQA) can reach the same promising scaling behaviour using much less computational resources. For the VQE, we find reasonable results in approximating the ground state energy of the Heisenberg model when suitable choices of initial states and parameters are used. Our design and implementation of a general quasi-dynamical evolution further improves these results.

Authors 6

1. Dennis Willsch

   Forschungszentrum Jülich · Jülich Supercomputing Centre

   Affiliation as printed

   Institute for Advanced Simulation , Jülich Supercomputing Centre , Forschungszentrum Jülich , 52425 Jülich , Germany

2. Manpreet Singh Jattana Aachen

   Forschungszentrum Jülich · Jülich Supercomputing Centre · RWTH Aachen University

   Affiliation as printed

   Institute for Advanced Simulation , Jülich Supercomputing Centre , Forschungszentrum Jülich , 52425 Jülich , Germany

   RWTH Aachen University , 52056 Aachen , Germany

3. Madita Willsch

   Forschungszentrum Jülich · Jülich Supercomputing Centre

   Affiliation as printed

   AIDAS , 52425 Jülich , Germany

   Institute for Advanced Simulation , Jülich Supercomputing Centre , Forschungszentrum Jülich , 52425 Jülich , Germany

4. Sebastian Schulz Aachen

   Forschungszentrum Jülich · Jülich Supercomputing Centre · RWTH Aachen University

   Affiliation as printed

   Institute for Advanced Simulation , Jülich Supercomputing Centre , Forschungszentrum Jülich , 52425 Jülich , Germany

   RWTH Aachen University , 52056 Aachen , Germany

5. Fengping Jin

   Forschungszentrum Jülich · Jülich Supercomputing Centre

   Affiliation as printed

   Institute for Advanced Simulation , Jülich Supercomputing Centre , Forschungszentrum Jülich , 52425 Jülich , Germany

6. Kristel F. L. Michielsen