Re-visiting supersymmetric Janus solutions: a perturbative construction

We construct holographic Janus solutions, which describe a conformal interface in the theory of M2-branes, in four-dimensional gauged supergravities using a perturbative method. In particular, we study three Einsteinscalar systems and their BPS equations, which are derived by Bobev, Pilch, and Warner(2014). The actions of our interest are all consistent truncations of D=11 supergravity, chosen to be invariant under SO(4)×SO(4),SU(3)×U(1)×U(1), and G2symmetry subgroups of SO(8). The utility of our semi-analytic result is illustrated by the calculation of minimal area surface and the associated holographic entanglement entropy.