@article {1859, title = {Mapping contrained optimization problems to quantum annealing with application to fault diagnosis}, journal = {Frontiers in ICT}, volume = {3}, year = {2016}, month = {2016/07/28}, pages = {14}, abstract = {

Current quantum annealing (QA) hardware suffers from practical limitations such as finite\ temperature, sparse connectivity, small qubit numbers, and control error. We propose new algorithms for\ mapping Boolean constraint satisfaction problems (CSPs) onto QA hardware mitigating these limitations.\ In particular, we develop a new embedding algorithm for mapping a CSP onto a hardware Ising model with\ a fixed sparse set of interactions and propose two new decomposition algorithms for solving problems too\ large to map directly into hardware. The mapping technique is locally structured, as hardware compatible\ Ising models are generated for each problem constraint, and variables appearing in different constraints are\ chained together using ferromagnetic couplings. By contrast, global embedding techniques generate a\ hardware-independent Ising model for all the constraints, and then use a minor-embedding algorithm to\ generate\ a hardware compatible Ising model. We give an example of a class of CSPs for which the scaling\ performance\ of the D-Wave hardware using the local mapping technique is significantly better than global\ embedding. We validate\ the approach by applying D- Wave\’s QA hardware to circuit-based fault diagnosis.\ For circuits that embed directly, we\ find that the hardware is typically able to find all solutions from a\ min-fault diagnosis set of size N using 1000 N samples,\ using an annealing rate that is 25 times faster than\ a leading SAT-based sampling method. Furthermore, we apply\ decomposition algorithms to find min-cardinality\ faults for circuits that are up to 5 times larger than can be solved directly on current hardware.

}, url = {http://journal.frontiersin.org/article/10.3389/fict.2016.00014/full}, author = {Bian, Zhengbing and Chudak, Fabian and Robert Brian Israel and Brad Lackey and Macready, William G and Aiden Roy} }