  Studying the collective excitations in charge neutral graphene (CNG) has
recently attracted a great interest because of unusual mechanisms of the charge
carrier dynamics. The latter can play a crucial role, for instance, for
superconducting phases in the periodically strained CNG and the magic angle
twisted bilayer graphene or for formation of graphene plasmon polaritons (GPPs)
associated with interband transitions due to the strain-induced pseudomagnetic
field. Importantly, GPP in CNG can be a tool providing new insights into
various intriguing quantum phenomena in CNG via optical experiments. However,
interband GPPs in CNG are barely investigated, even in the simplest
configurations. Here, we show that magnetically biased single layer CNG
(particularly, at zero temperature) can support interband GPPs of both
transverse magnetic and transverse electric polarizations. They exist inside
the narrow absorption bands originating from the electronic transitions between
Landau levels and are tunable by the external magnetic field. We put our study
into the context of potential near-field and far-field optical experiments,
thus opening the door to the exploration of CNG for optics and nanophotonics.
