# Modernizing Quantum Annealing using Local Searches. (arXiv:1606.06833v4 [quant-ph] UPDATED)

I describe how real quantum annealers may be used to perform local (in state

space) searches around specified states, rather than the global searches

traditionally implemented in the quantum annealing algorithm. Such protocols

will have numerous advantages over simple quantum annealing. By using such

searches the effect of problem mis-specification can be reduced, as only energy

differences between the searched states will be relevant. The quantum annealing

algorithm is an analogue of simulated annealing, a classical numerical

technique which has now been superseded. Hence, I explore two strategies to use

an annealer in a way which takes advantage of modern classical optimization

algorithms. Specifically, I show how sequential calls to quantum annealers can

be used to construct analogues of population annealing and parallel tempering

which use quantum searches as subroutines. The techniques given here can be

applied not only to optimization, but also to sampling. I examine the

feasibility of these protocols on real devices and note that implementing such

protocols should require minimal if any change to the current design of the

flux qubit-based annealers by D-Wave Systems Inc. I further provide

proof-of-principle numerical experiments based on quantum Monte Carlo that

demonstrate simple examples of the discussed techniques.