  Great progress has been made in the field of quantum inertial sensors, from
the laboratory to the real-world use, which will ultimately require sensor
miniaturization and ruggedization for dynamic motion. However, lateral atomic
movement with respect to the sensing axis limits inertial sensing, which
inspires the atom guides to ensure transverse atomic confinement. Compared to a
relatively large free-space optical mode, an evanescent field (EF) mode with an
advantageously small mode area allows for stronger atom-light interactions and
lower optical power requirements for the atom guides. We study EF atom guides
in nanofibers and waveguides with traveling evanescent waves, rather than EF
optical lattices with standing evanescent waves. Our preliminary demonstration
of an EF atom guide takes place on a nanofiber using 685 nm and 937 nm lights,
and we experimentally show that the atomic coherence of the EF atom guide
(685/937 nm) is similar to the EF optical lattice. By replacing the 685 nm
light with 793 nm light, we further demonstrate the sub-5mW EF atom guide
(793/937 nm) on nanofibers and assess relative power reduction of 61$\%$ on
nanofibers and 78$\%$ on membrane waveguides, compared to nanofibers (685/937
nm), for the same optical potential depth. Power reduction is beneficial for
reducing total optical power requirements and improving heat dissipation in
vacuum for atom guiding on chip-based membrane-photonic devices. To connect
this work with EF-guided atom interferometry, we evaluate the viability and
potential benefits of using the low-power light configuration on membrane
waveguides, presenting fabricated linear and circular waveguides for future
demonstrations. This is a promising step towards a chip-scale quantum inertial
sensor array with reduced size, weight, and power.
