  An SDW antiferromagnetic (SDW-AF) low temperature phase transition is
generally observe and the AF spin fluctuations are considered to play an
important role for the superconductivity paring mechanism in FeAs
superconductors. However, a similar magnetic phase transition is not observed
in FeSe superconductors, which has caused considerable discussion. We report on
the intrinsic electronic states of FeSe as elucidated by transport measurements
under magnetic fields using a high quality single crystal. A mobility spectrum
analysis, an ab initio method that does not make assumptions on the transport
parameters in a multicarrier system, provides very import and clear evidence
that another hidden order, most likely the symmetry broken from the tetragonal
C4 symmetry to the C2 symmetry nematicity associated with the selective
d-orbital splitting, exists in the case of superconducting FeSe other than the
AF magnetic order spin fluctuations. The intrinsic low temperature phase in
FeSe is in the almost compensated semimetallic states but is additionally
accompanied by Dirac cone like ultrafast electrons $\sim$
10$^4$cm$^2$(VS)$^{-1}$ as minority carriers.
