Abstract: Computer systems and methods for constructing a model of the noise afflicting a quantum computer comprising a plurality of qubits are provided. A graph G that describes a conditional independence structure of the noise is obtained. The graph G includes a node for each qubit in the plurality of qubits. The noise afflicting the quantum computer is logically reduced to Pauli noise. The graph G is broken into a plurality of sets. Each respective set Cj in the plurality of sets (i) corresponds a respective qubit j in the plurality of qubits and (ii) comprises a representation of the respective qubit j and the parent qubits ?+j in the graph G. For each respective set Cj in the plurality of sets, a corresponding local conditional probability distribution Pr(ej|e?+j) is characterized in which ej?j is a Pauli error on the jth qubit.

Abstract: A quantum computational (QC) device includes a multi-qubit (MQ) structure and another MQ structure coupled to the MQ structure. The MQ structure is arranged to provide an adiabatic quantum computation by application of an initial Hamiltonian operator. The other MQ structure is arranged to provide another adiabatic quantum computation by application of another Hamiltonian operator that is spatially different than the initial Hamiltonian operator.