anti_crossing_loops(num_variables: int) dimod.binary.binary_quadratic_model.BinaryQuadraticModel[source]

Generate an anti-crossing problem with two loops.

This is the problem studied in [DJA].

Note that for small values of num_variables, the loops can be as small as a single edge.

The ground state of this problem is +1 for all variables.


num_variables – Number of variables used to generate the problem. Must be an even number greater than or equal to 8.


A binary quadratic model.


Dickson, N., Johnson, M., Amin, M. et al. Thermally assisted quantum annealing of a 16-qubit problem. Nat Commun 4, 1903 (2013). https://doi.org/10.1038/ncomms2920