  We show that single-atoms can be trapped on the surface of a
subwavelength-diameter silica-fiber, an optical nanofiber, without any external
field, and that single photons spontaneously emitted from the atoms can be
readily detected through the single guided-mode of the nanofiber. A key point
of the work is our finding that atom trapping sites are created on the
nanofiber surface by irradiating the atom cloud around the nanofiber with a
violet laser radiation.
