Hierarchical Multigrid Ansatz for Variational Quantum Algorithms

Quantum computing is an emerging topic in engineering that promises to enhance supercomputing using fundamental physics. In the near term, the best candidate algorithms for achieving this advantage are variational quantum algorithms (VQAs). We design and numerically evaluate a novel ansatz for VQAs, focusing in particular on the variational quantum eigensolver (VQE). As our ansatz is inspired by classical multigrid hierarchy methods, we call it "multigrid" ansatz. The multigrid ansatz creates a parameterized quantum circuit for a quantum problem on n qubits by successively building and optimizing circuits for smaller qubit counts jContributors:

• Stephan Eidenbenz
• Andreas Bärtschi
• Daniel O'Malley
• John Golden
• Satyajayant Misra