2 research outputs found
Computational Complexity of Determining the Barriers to Interface Motion in Random Systems
The low-temperature driven or thermally activated motion of several condensed
matter systems is often modeled by the dynamics of interfaces (co-dimension-1
elastic manifolds) subject to a random potential. Two characteristic
quantitative features of the energy landscape of such a many-degree-of-freedom
system are the ground-state energy and the magnitude of the energy barriers
between given configurations. While the numerical determination of the former
can be accomplished in time polynomial in the system size, it is shown here
that the problem of determining the latter quantity is NP-complete. Exact
computation of barriers is therefore (almost certainly) much more difficult
than determining the exact ground states of interfaces.Comment: 8 pages, figures included, to appear in Phys. Rev.