  Symmetry plays a fundamental role in our understanding of both conventional
symmetry breaking phases and the more exotic quantum and topological phases of
matter. We explore the experimental signatures of symmetry enriched U(1)
quantum spin liquids (QSLs) on the pyrochlore lattice. We point out that the Ce
local moment of the newly discovered pyrochlore QSL candidate
Ce$_2$Sn$_2$O$_7$, is a dipole-octupole doublet. The generic model for these
unusual doublets supports two distinct symmetry enriched U(1) QSL ground states
in the corresponding quantum spin ice regimes. These two U(1) QSLs are dubbed
dipolar U(1) QSL and octupolar U(1) QSL. While the dipolar U(1) QSL has been
discussed in many contexts, the octupolar U(1) QSL is rather unique. Based on
the symmetry properties of the dipole-octupole doublets, we predict the
peculiar physical properties of the octupolar U(1) QSL, elucidating the unique
spectroscopic properties in the externalmagnetic fields. We further predict the
Anderson-Higgs transition from the octupolar U(1) QSL driven by the external
magnetic fields. We identify the experimental relevance with the candidate
material Ce$_2$Sn$_2$O$_7$ and other dipole-octupole doublet systems.
