The equation of state (EoS) for cold dense matter inside neutron stars is
investigated by using holographic QCD models in the framework of the
Einstein-Maxwell-dilaton (EMD) system and the improved Karch-Katz-Son-Stephanov
(KKSS) action for matter part. This method of describing holographic nuclear
matter in the EMD$+$ KKSS framework is different from that by using the
Dirac-Born-Infeld (DBI) action and the Chern-Simons (CS) terms. Combining with
the Hebeler-Lattimer-Pethick-Schwenk (HLPS) intermediate equation of state
(EoS), the hybrid EoS inside the neutron stars is constructed. The obtained
hybrid EoS is located in the range that is defined by the low-density chiral
effective theory, the high-density perturbative QCD, and the polytropic
interpolations between them, and is constrained by the astrophysics
observations. The square of the sound velocity reaches a maximum value larger
than $0.8$ in the region of $2-5$ times the saturation baryon number density
and approaches the conformal limit at the high baryon density range. The
mass-radius relation and the tidal deformability of the neutron stars are in
agreement with astrophysical measurements. The possible maximum mass for the
neutron star is about $2.5{M}_{\odot}$ and the radius is about $12\mathrm{km}$
then. It is noticed that the holographic quark matter branch in the mass-radius
relation is always unstable and the holographic nuclear matter can produce a
stable branch. These results indicate that even in the core of the NS, the
matter is still in the confinement phase and the quark matter is not favored.