## Dual Time Scales in Simulated Annealing of a Two-dimensional Ising Spin Glass

**Speaker:**Na Xu

**When:**October 17, 2016 (Mon), 03:00PM to 04:00PM (add to my calendar)

**Location:**SCI 328

*This event is part of the Departmental Seminars. *

We apply a generalized Kibble-Zurek out-of-equilibrium scaling ansatz to simulated annealing when approaching the spin-glass transition at temperature T = 0 of the two-dimensional Ising model with random J = +/-1 couplings. Analyzing the spin-glass order parameter and the excess energy as functions of the system size and the annealing velocity, we found scaling where the energy relaxes slower than the order parameter, i.e., there are two different dynamic exponents. We argue that such behavior arises as a consequence of the entropy-driven ordering mechanism within droplet theory. In the context of optimization, our study provides an example of robust dense-region solutions for which the excess energy (the conventional cost function) may not be the best measure of success. http://arxiv.org/abs/1609.09024

Dissertation Committee: Anders Sandvik, Claudio Chamon, Anatoli Polkovnikov, Alex Sushkov, Robert Carey