The stability, with respect to dislocations, of the elastic phase (Bragg glass) of a randomly pinned elastic medium in 2 dimensions was studied by using the minimum-cost flow algorithm for a disordered fully-packed loop model. The elastic phase was found to be unstable against dislocations; due to the quenched disorder. The energetics of dislocations were considered within the framework of renormalization-group predictions, as well as in terms of a domain-wall formalism.

Absence of Two-Dimensional Bragg Glasses. C.Zeng, P.L.Leath, D.S.Fisher: Physical Review Letters, 1999, 82[9], 1935-8