What is TitanQ

This is the official documentation for the TitanQ Python SDK

Solver background

The Ising Model is a lattice spin system. Each spin has a scalar interaction between every other spin, and spins are quadratically coupled. Finding the energy minimum of the Ising model problem is a non-convex optimization problem with many local minima. It can be modeled probabilistically by taking the exponential of the energy function. The spin values are usually constrained to being bipolar {-1, 1}, representing up and down spin values. In the context of Optimization problems the Ising Model has also been referred to as the Quadratic Unconstrained Binary Optimization (QUBO) problem. The problem formulation is the same, but the variables usually take binary values of {0, 1}. This mapping has been variously applied to problems such as the MAX-CUT problem, Travelling Salesman Problem, Quadratic Assignment Problem, Set Assignment Problem, and many others. In the optimization context, each variable in the QUBO model system usually corresponds to a decision variable, (i.e. Xi might correspond to whether node i is on on the right or the left side of the cut in a MAX-CUT problem). For this solver, the expected input format is a matrix (weights) that is symmetric with diagonal zero entries and a row vector of bias values (bias).