A magnetic recording-reproducing apparatus has a magnetic recording medium having
a nonmagnetic substrate, and a functional layer and a recording layer formed on
the nonmagnetic substrate, the recording layer exhibiting a magnetic anisotropy
energy density KuRL, the functional layer developing ferromagnetism
upon irradiation with light so as to exhibit a magnetic anisotropy energy density
KuFL lower than the magnetic anisotropy energy density KuRL and
the functional layer serving to lower the magnetic anisotropy energy density of
the recording layer through exchange coupling interaction with the recording layer
when the functional layer is irradiated with light, a light source which irradiates
the functional layer with light, and a magnetic head having a writing head writing
signal magnetization by applying a magnetic field to the recording layer and a
reading head reading the signal magnetization recorded in the recording layer.
