For three-dimensional ABJ(M) theories and N=4 Chern-Simons-matter
quiver theories, we construct two sets of 1/2 BPS Wilson loop operators by
applying the Higgsing procedure along independent directions of the moduli
space, and choosing different massive modes. For theories whose dual M-theory
description is known, we also determine the corresponding spectrum of 1/2 BPS
M2-brane solutions. We identify the supercharges in M-theory and field theory,
as well as the supercharges preserved by M2-/anti-M2-branes and 1/2 BPS Wilson
loops. In particular, in N=4 orbifold ABJM theory we find pairs of
different 1/2 BPS Wilson loops that preserve exactly the same set of
supercharges. In field theory they arise by Higgsing with the choice of either
particles or antiparticles, whereas in the dual description they correspond to
a pair of M2-/anti-M2-branes localized at different positions in the compact
space. This result enlightens the origin of classical Wilson loop degeneracy in
these theories, already discussed in arXiv:1506.07614. A discussion on possible
scenarios that emerge by comparison with localization results is included.Comment: 52 pages, 4 figures; V2, 61 pages, 4 figures, supercharges in gravity
and field theory identified, conclusion unchanged, published versio