Vortex Loop Operators, M2-branes and Holography

We construct vortex loop operators in the three-dimensional N = 6 supersymmetric Chern-Simons theory recently constructed by Aharony, Bergman, Jafferis and Maldacena. These disorder loop operators are specified by a vortex-like singularity for the scalar and gauge fields along a one dimensional curve in spacetime. We identify the 1/2, 1/3 and 1/6 BPS loop operators in the Chern-Simons theory with excitations of M-theory corresponding to M2-branes ending along a curve on the boundary of AdS_4 x S^7/Z_k. The vortex loop operators can also be given a purely geometric description in terms of regular "bubbling" solutions of eleven dimensional supergravity which are asymptotically AdS_4 x S^7/Z_k.
Comment: 62 pages; v2 references added; v3 resolved remaining issue regarding odd k, version to appear in JHEP; v4 correction to VEV calculation in sec. 3