Variational problems in phase transition systems centre on energy functionals that balance interfacial costs and bulk or nonlocal interactions to determine collective patterns of coexisting phases.

For the past six years, Los Alamos National Laboratory has led the world in trying to understand one of the most frustrating barriers that faces variational quantum computing: the barren plateau.

Variational methods in discrete boundary value problems encompass a suite of analytical techniques that recast difference equations with prescribed endpoint conditions into optimisation problems for ...