Calibration of quantum processor operator parameters

An apparatus comprising one or more classical computers and one or more classical storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more classical computers to perform operations comprising:

• for a quantum processor having a plurality of interacting qubits represented by a graph comprising nodes and edges, wherein each node represents a respective qubit and is associated with a value representing an operating parameter of the respective qubit, and wherein each edge represents a respective interaction between two qubits and is associated with a value representing an operating parameter of the respective interaction:
• selecting a graph traversal algorithm that traverses the graph based on a traversal rule;
• identifying one or multiple disjoint subsets of nodes or one or multiple disjoint subsets of edges, wherein nodes in a subset of nodes are related via the traversal rule and edges in a subset of edges are related via the traversal rule;
• determining calibrated values for the nodes or edges in each subset, comprising, for each subset:
• selecting a seed node or a seed edge in the subset;
• stepwise, for the selected seed node or seed edge, and for each subsequent node or edge:
• performing a constrained optimization using i) an objective function for the node or edge, and ii) one or more constraints based on a calibrated operating parameter mapping comprising calibrated values of nodes or edges in the graph, to determine a calibrated value for the node or edge;
• determining whether each node or edge in the subset has been calibrated;
• in response to determining that each node or edge in the subset has not been calibrated, traversing the graph based on the traversal rule to select a subsequent node or edge for the step.