Print Email Facebook Twitter Experimental error mitigation via symmetry verification in a variational quantum eigensolver Title Experimental error mitigation via symmetry verification in a variational quantum eigensolver Author Sagastizabal, R.E. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Bonet Monroig, X. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Universiteit Leiden) Singh, Malay (Student TU Delft; Kavli institute of nanoscience Delft) Rol, M.A. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Bultink, C.C. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Fu, X. (TU Delft FTQC/Bertels Lab; TU Delft Computer Engineering; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Ostroukh, V.P. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Muthusubramanian, N. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Bruno, A. (TU Delft QCD/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Beekman, M.C. (TU Delft Business Development; Kavli institute of nanoscience Delft) Haider, S.N. (TU Delft Business Development; TNO) O'Brien, T.E. (Universiteit Leiden) DiCarlo, L. (TU Delft QCD/DiCarlo Lab; TU Delft QN/DiCarlo Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Department Business Development Date 2019 Abstract Variational quantum eigensolvers offer a small-scale testbed to demonstrate the performance of error mitigation techniques with low experimental overhead. We present successful error mitigation by applying the recently proposed symmetry verification technique to the experimental estimation of the ground-state energy and ground state of the hydrogen molecule. A finely adjustable exchange interaction between two qubits in a circuit QED processor efficiently prepares variational ansatz states in the single-excitation subspace respecting the parity symmetry of the qubit-mapped Hamiltonian. Symmetry verification improves the energy and state estimates by mitigating the effects of qubit relaxation and residual qubit excitation, which violate the symmetry. A full-density-matrix simulation matching the experiment dissects the contribution of these mechanisms from other calibrated error sources. Enforcing positivity of the measured density matrix via scalable convex optimization correlates the energy and state estimate improvements when using symmetry verification, with interesting implications for determining system properties beyond the ground-state energy. To reference this document use: http://resolver.tudelft.nl/uuid:2a9b2e13-8e1e-4d09-a2b3-33a6aeff44bd DOI https://doi.org/10.1103/PhysRevA.100.010302 ISSN 2469-9926 Source Physical Review A: covering atomic, molecular, and optical physics and quantum information, 100 (1) Part of collection Institutional Repository Document type journal article Rights © 2019 R.E. Sagastizabal, X. Bonet Monroig, Malay Singh, M.A. Rol, C.C. Bultink, X. Fu, V.P. Ostroukh, N. Muthusubramanian, A. Bruno, M.C. Beekman, S.N. Haider, T.E. O'Brien, L. DiCarlo Files PDF PhysRevA.100.010302.pdf 1.17 MB Close viewer /islandora/object/uuid:2a9b2e13-8e1e-4d09-a2b3-33a6aeff44bd/datastream/OBJ/view