Three dimensional SCFT from M2 branes at conifold singularities

Recently, it was conjectured that parallel branes at conical singularities are related to string/M theory on AdS x X where X is an Einstein manifold. In this paper we consider coincident M2 branes near a conifold singularity when M theory is compactified on AdS(4) x Q(1,1,1), where Q(1,1,1) = (SU(2) x SU(2) x SU(2))/(U(1) x U(1)) is a seven dimensional Sasaki-Einstein mani fold. We argue that M theory on AdS(4) x Q(1,1,1) is dual to a three dimens ional superconformal field theory. We use the fact that the three dimension al self-mirror duality is preserved by exact marginal operators, as observe d by Strassler.