  Symmetry-protected trivial (SPt) phases of matter are the product-state
analogue of symmetry-protected topological (SPT) phases. This means, SPt phases
can be adiabatically connected to a product state by some path that preserves
the protecting symmetry. Moreover, SPt and SPT phases can be adiabatically
connected to each other when interaction terms that break the symmetries
protecting the SPT order are added in the Hamiltonian. It is also known that
spin-1 SPT phases in quantum spin chains can emerge as effective intermediate
phases of spin-2 Hamiltonians. In this paper we show that a similar scenario is
also valid for SPt phases. More precisely, we show that for a given spin-2
quantum chain, effective intermediate spin-1 SPt phases emerge in some regions
of the phase diagram, these also being adiabatically connected to non-trivial
intermediate SPT phases. We characterize the phase diagram of our model by
studying quantities such as the entanglement entropy, symmetry-related order
parameters, and 1-site fidelities. Our numerical analysis uses Matrix Product
States (MPS) and the infinite Time-Evolving Block Decimation (iTEBD) method to
approximate ground states of the system in the thermodynamic limit. Moreover,
we provide a field theory description of the possible quantum phase transitions
between the SPt phases. Together with the numerical results, such a description
shows that the transitions may be described by Conformal Field Theories (CFT)
with central charge c=1. Our results are in agreement, and further generalize,
those in [Y. Fuji, F. Pollmann, M. Oshikawa, Phys. Rev. Lett. 114, 177204
(2015)].
